Test Shaft 09

"All these science spheres are made out of asbestos, by the way. Keeps out the rats. Let us know if you feel a shortness of breath, a persistent dry cough, or your heart stopping. Because that's not part of the test. That's asbestos."

- Cave Johnson

Test Shaft 09, codenamed "Zulu Bunsen," is the last in a group of nine Enrichment Shafts reaching lower than 4375 m up from the deepest parts of the salt mine in and above where the Aperture Science Enrichment Center is located, and featured in the Portal 2 chapters The Fall and The Reunion.

It can be considered as a "timeline" level, as it reveals many details about Aperture Science's background and evolution, from its establishment in the late 1940s to the end of the pre-GLaDOS era in the late 1980s.

Overview
As part of the Enrichment Shafts built in the immense salt mine purchased by Cave Johnson in 1944, Test Shaft 09 was used to test several experiments from the early 1950s to the late 1980s, many being described by Johnson through pre-recorded interphone messages, not necessarily involving teleportation, often with ominous results, and spread through six Enrichment Spheres (the seventh apparently not being used), as well as several other unseen Test Chambers:


 * In the Enrichment Spheres: Experiments with the Mobility Gels (in the co-op Test Shaft as well) coupled with prototypes of the Handheld Portal Device, from the 50s to the 80s. Testing starts in a 50s area at the bottom of the Shaft and goes ascending in height as well as time to end up in the 80s, then finally the modern facility again. Thus during the ~35 years of building of the Shaft, each area was left as it was when built and never modernized when the next area was constructed.


 * In the condemned Test Chambers near the 50s reception area:


 * Injection of praying mantis DNA to Test Subjects, turning them into Mantis Men, to be fought by other Test Subjects.
 * Experiment having a Test Subject's blood replaced with pure gasoline by shooting at them with an invisible laser.
 * Experiment having Test Subject's excrements temporarily turning into coal.
 * Experiment during which a superconductor is turned up full blast and pointed at a Test Subject, with unknown results, the best-case scenario having the Test Subject getting some superpowers, or, in the worst case, some tumors, which Aperture will remove.


 * In the Test Chambers near the 70s reception area:


 * Experiment having a Test Subject's blood replaced by peanut water for a few minutes, which cannot be performed if the Test Subject is allergic to peanut. Johnson states a new type of Nobel Prize will have to be invented just for them if the experiment succeeds.
 * Experiment having a Test Subject's percentage of body water brought from 60% to 20 to 30% when being hit with jet engines.
 * Teleportation experiment which may have a Test Subject's skin removed after the teleportation process. Before the test, Test Subject are asked to remember what type of skin they have in case it is removed during teleportation, and Cave promises Test Subjects will be sewn right back into it.
 * Unknown experiment in the icebreaker Borealis in a large drydock located near the previous Test Chambers, which made the ship disappear and reappear in an Arctic region.

On June 15, 1961, Test Shaft 09 was condemned by vitrification when the shaft was filled with unsafe quantities of cosmic ray spallation elements, until it was reopened in the early 1970s. Anyone entering the area is warned to not look at, touch, ingest or engage conversation with any substances located beyond. In the 1990s, Cave Johnson is dead, and the Enrichment Shafts are apparently disused, the main facility above, eventually supervised by GLaDOS, being used instead for testing.

As the Enrichment Shafts date from before GLaDOS' activation, she never monitored them before discovering Test Shaft 09 with Chell. Instead, pre-recorded messages from Aperture CEO Cave Johnson and his assistant Caroline are used to guide Test Subjects.

Access
Test Shaft 09 has several accesses: the Main Lift that connects the lowest parts to the surface, and that was to be used by Test Subjects; the Abandonment Hatch, a gargantuan hatch accessed by Chell from the "Tartaros" area at the very bottom; the Transition Seal 02, another hatch located at the very top; and an underground train network connected to Test Shafts 01 to 08, located at the very bottom of the Shaft series.

Reception and control complexes
Test Shaft 09 contains several complexes dedicated to office space, reception for Test Subjects, and access control to the Enrichment Spheres. These complexes can be distinguished by era: the reception complex for the Repulsion Gel spheres was completed in the early 1950s and reflects a time when Aperture (at that time marketing its products as "Aperture Science Innovators") was able to attract the best and brightest to test its exotic technologies. Instructional posters, Johnson's pre-recorded messages and the awards seen in the case featured in the lobby suggest a time of pride and optimism for the company.

The complex for the Propulsion Gel spheres was completed in the early 1970s after Aperture suffered major financial and legal setbacks, as well as (according to Johnson) industry espionage by competitor Black Mesa. Offices are decorated in brown, yellow and orange paneling typical of 1970s America. Posters caution employees to notify their supervisors if they spot inspectors from any of a long list of government safety agencies. In his messages, Johnson complains about having to hire hobos off the street at $60 per test.

The complex for the Conversion Gel spheres was completed in the early 1980s when Aperture had begun to replace its employees with robots, leaving the employees themselves to act as Test Subjects. Posters motivate human employees to accept their robotic replacements and give advice on how to deal with rogue artificial intelligences.

Enrichment Spheres
Test Shaft 09 is mostly filled with 7 large geodesic asbestos and steel spheres located one above the other, and containing the original chambers used by Aperture Science Innovators for tests of its Mobility Gels in conjunction with ancestors of the modern Handheld Portal Device. The spheres contain multiple testing rooms supported by steel pylons and connected by catwalks. Spheres also contain offices and observation rooms around their periphery. Elevators provide transport between spheres.

Most of the testing spheres and the bottom of the shaft itself contain pools of highly corrosive toxic waste. The signs warning not to fall into the waste suggest it has been there from the start, but may have been instrumental in the sealing of the shaft.

Other Test Chambers
Experiments that did not require the space or modularity of the portal/gel tests were located in side chambers accessed by heavy doors near the '50s and '70s-era reception areas. Almost all of these chambers have been vitrified. Cave Johnson's prerecorded messages near these doors describe absurd side effects mentioned above. Of particular interest is an unsealed door leading to the drydock of the missing Borealis.

Pumping Stations
The shaft also contains several Pumping Stations codenamed Alpha, Beta, and Gamma which pump the three Mobility Gels up the shaft and into various testing chambers (each bearing the color of its related gel), suggesting a huge reserve of Mobility Gels must be located somewhere in the salt mine. These stations were taken offline when the shaft was abandoned, but are reactivated by Chell during her journey. The stations are in surprisingly good repair given the amount of time passed since they were last maintained. The catwalks have decayed, but the pipe system has survived with only a few broken valves and leaking flanges.

The gel pipe network was also designed to feed into the modern Enrichment Center through the Gel Pump Station at the top of Test Shaft 09, and Chell restores this connection when she opens the Transition Seal 02 located in the station.

Tartaros


In the Central AI Chamber at the end of the Portal 2 chapter The Escape, Wheatley plugs GLaDOS' memory to a potato, and put her with Chell in the elevator connected to the chamber. As GLaDOS explains him who he really is and calls him a moron, he has a fit of rage, and smashes the elevator several times until it is set loose into the shaft. The next chapter, The Fall, opens as Chell and the now potato-powered GLaDOS fall into the 4375 meter-deep elevator shaft, an employee access to Test Shaft 09. During the fall, GLaDOS tells Chell more about Wheatley's background and how him being in charge of the facility is a catastrophe. At the end of the fall, the lowest part of the shaft appears to be destroyed and does not reach the floor; Chell and GLaDOS fall onto the ground, and Chell passes out. When she wakes up, she witnesses GLaDOS being pecked by the crow who quickly takes her away, and the elevator dangling at the end of the destroyed shaft up above.

Chell then proceeds to an area that seems part ruined / part in construction, one of the two entrances to Test Shaft 09 to be used only by employees. Large pillars appear to support the modern facility above, and are marked with the number "09" and the name "Tartaros". In the Greek mythology, Tartarus is a large gloomy pit or abyss used as a dungeon of torment and suffering that resides beneath the underworld, and where several Titans were sent by Zeus for punishment; this is paralleled here, with Chell being sent in large gloomy abysses as a punishment from Wheatley. "09" is probably related to this particular area of the mines, since the Enrichment Shaft located nearby bears the same number.

Aided by her ASHPD creating portals on the working surfaces, Chell proceeds through the area, which is still fully powered, with ongoing fires of carcasses of Sentry Turrets. Many red cranes can be seen. Many other pillars and cranes appear to extend very far under the facility, possibly in areas bearing other numbers. The whole area seems to be uncompleted, as many scaffolds are still in place.

Chell then finds herself facing a wall barring the way to the "condemned testing area" of Test Shaft 09, with three small shut doors. There two signs indicate the current status and condemnation date of the shaft mentioned above. Many "Keep out" and "Do not enter signs" are placed. Conversion Gel pipes are also seen coming from above, disappearing later into the rock. Thanks to her portal gun, Chell easily circumvents the wall, and proceeds through a narrow path along with a pipe runs, until she reaches the Abandonment Hatch.

Abandonment Hatch
The Abandonment Hatch is a gargantuan metal hatch that seals Test Shaft 09 from that part of the facility. There the condemnation date is seen again. To open it, two persons have four seconds to press the two "Hatch Reclusion Override" buttons each found in the two cabins located on left and right of the hatch, each with a countdown outside of them. As Chell is alone, she uses her portals to push both buttons. When the hatch opens, it reveals it was hiding only a small human-size door, the rest of the hatch size being a mere wall. Beyond the door is a small corridor leading to another small door, itself leading to the very bottom of Test Shaft 09 itself.

1950s levels: Repulsion Gels
The Mobility Gel tested in this level era is the Repulsion Gel.

1952: Entrance Way, Lobby and Testing Lounge
The proper way to reach that part (i.e. the Test Subject way) is by arriving from the Main Lift from the surface. It will lead to the reception area (Sublevel 193), which is made of the Entrance Way, the Lobby and the Testing Lounge.

Chell however arrives directly into the shaft itself from the Abandonment Hatch (which is restricted to employees), where she can see the first two Enrichment Spheres, a sign warning to not fall into the toxic waste filled with six small spheres and a destroyed "Aperture Science Innovators" metal logo that fell from above, and the building date, 1952, on a wall. A catwalk leads to another level, where three doors leading to contaminated and vitrified areas are found. The first one, breached by the collapsed sealing, is an employee door leading to the reception area, with breaker 135B that will restore power to the reception area. The second door leads to Test Chambers 1 to 200. It has a notice stating the experiment was discontinued, with the image of an Enrichment Sphere filled with cement, suggesting other spheres (maybe smaller like the ones in the water) could be located there, and that Aperture must have been running an incredible amount of other unknown experiments. The third door leads to the underground train network linking all shafts together. Near the door is also a notice with an Enrichment Sphere filled with cement, placed there for unknown reasons.

Entrance Way
Back to the reception area, the Main Lift shaft is empty and condemned, and the elevator, located several hundreds of meters above, is out of order until a undetermined date. Back in the 1950s, Test Subjects leaving the Main Lift would reach the Entrance Way and meet a sign with on it "Aperture Science Innovators" (Aperture's trademark, created in 1947, and later renamed to "Aperture Laboratories") and "Welcome to the future of tomorrow!" above, with a mountain skyline as a background, as well as a larger Aperture Science Innovators faded blue metal logo, the same as the one that fell into the shaft's bottom. A catwalk through the Entrance Way, carved into the rock, would lead to the Lobby and Testing Lounge. Aperture CEO Cave Johnson would greet Test Subjects with great enthusiasm, joined with his assistant Caroline, in the following pre-recorded announcement, accompanied with an early rendition of the music heard in the Aperture Investment Opportunity videos and the television in Chell's chamber in the Extended Relaxation Center:

When Chell visits the place however, the catwalk leading to the Lobby has been destroyed, and she must portal herself through the gap by using momentum and going through the Aperture Science Innovators sign, after the nuclear logo in its center detaches itself.

Lobby
Upon reaching the lobby, Test Subjects would be greeted by this message:

The Lobby is a room with black marble and and a maroon carpet on the floor and wooden panes on the walls. Four lamps with spherical lampshades hang from the ceiling. A sign asks Test Subjects to go to the small desk nearby and sign in with the receptionist before proceeding to the Lounge. Nearby is an elongated room filled with several desks equipped with typewriters and phones, probably used for registering candidates.

Testing Lounge
The Testing Lounge is accessed through a folder red curtain. Its floor is fully covered with maroon carpet, and it is filled with large conformable beige armchairs and ashtrays. It also has six spherical lamps on the ceiling. Of note is the large portrait of a young and brisk Cave Johnson placed between two cases. One of the cases has been broken and emptied; the other is filled with many items giving information about Aperture's background and evolution: four trophies, including the Spirit of Idaho 1955 award for the promotion of Potato Science, by the National Potato Board; the Shower Curtain Salesman of 1943 award for Aperture Fixtures; and two "Contractor of the Year - Runner Up" awards from the US Department of Defense, dated 1952 and 1954 (an unseen 1953 award can be found in the game files). The case also includes the main page of the newspaper The Up Pioneer Press, dated from a Thursday of January 1944, showing that Johnson purchased salt mines in Upper Michigan, where and above which the Aperture Science Enrichment Center will eventually be built. Under a picture of the mine, Johnson is quoted "The Future is Here, and it's Under the Earth's Crust". Finally, four framed awards can be seen: the Best New Science Company award 1947 given to Aperture Science by the Science and Business Institute of America; another Spirit of Idaho award by the National Potato Board Award for the promotion of Potato Science, undated; the Shower Curtain Salesman of 1943 award given to Cave Johnson for Aperture Fixtures; and finally an award for rank #2 for Aperture Science in the Top 100 Applied Science Companies 1949.

After leaving the Testing Lounge to the shaft proper, Test Subjects would go to an elevator operated by an attendant. Upstairs, a catwalk, now collapsed, would lead either to the small elevator going inside Enrichment Sphere 01, Pump Station Alpha, or three condemned Test Chambers, two vitrified (one of which filled with cement), the other apparently not condemned, although the door cannot be opened. Near each door leading to these chambers is an interphone, which when powered will give the following pre-recorded messages by Johnson about what tests they involve:

Pump Station Alpha
The first of the three Test Shaft 09's Mobility Gel Pump Stations, probably also built in 1952, is used to pump Repulsion Gel. It is actioned from a switch on a machine in a booth located at the lowest level, with a screen showing the six used Test Shaft 09 spheres. The booth contains three motivational posters: "Know your... Allergens", "Know your... Hazardous Materials", and "Know your... Chemical Hazards". Above on a catwalk leading back to the shaft can be found a safety poster saying "Together we can make 1956 the lowest unexpected casualty annum ever!". After powering back Pump Station Alpha, Chell portals herself near the small elevator leading to Enrichment Sphere 01 to begin her introduction to Aperture's Mobility Gels. At the entrance of the elevator is introduced an early iteration of the Material Emancipation Grill, the first of several early iterations of familiar Aperture technology.

Before entering the elevator, Test Subjects would hear the following message:

1953: Enrichment Sphere 01
Sphere 01 is in a fairly good condition. When the elevator stops, the Sphere is lit up, and reveal a "You are here sign" showing the number of Enrichment Shafts. Test Subjects were welcome by that Cave Johnson announcement:

Test Chamber 01
Outside this first Test Chamber can be found a building date, 1953, and a sign warning Test Subjects that the following test is unsolvable without an "Aperture Science Portable Quantum Tunneling Device", followed by the picture of a Test Subject wearing a large Handheld Portal Device prototype. Below the image a text states that any Test Subject must find a Test Associate to receive their Quantum Tunneling Device before participating in any Shaft 09 enrichment activities.

Inside the Test Chamber are introduced early iterations of familiar Aperture technologies, paired with the use of the Repulsion Gel: an early Weighted Storage Cube used with an early 1500 Megawatt Heavy Duty Super-Colliding Super Button, as well as an early vertical button, used to released the Cube through an early Vital Apparatus Vent. A short story about the Repulsion Gel is also found on a sign at the entrance of the Test Chamber, near the early iteration of the squared testing element sign, named "Aperture Science Fact Placard #00D45-01R - Repulsion Gel". After the test has been performed, the following message is played:

Test Chamber 02
The next Test Chamber was originally to be reached through several catwalks, but since they have collapsed, Chell must use her Portal Gun instead to reach the other side. Its construction appears to have started in 1953 and ended in 1956. Before entering, the following message is played:

A more elaborated test is proposed, with two walls covered in Repulsion Gel, having Test Subjects to bounce from one to the other to reach a Cube. Outside, the following message is played:

Then an elevator leads to Sphere 02.

1957: Enrichment Sphere 02
Here Test Subjects were introduced by the following message:

Test Chamber 01
Test Chamber 01 cannot be used as it collapsed on the wall, forcing Chell to reach the bottom of the Sphere then reach the second Test Chamber with portals.

Test Chamber 02
Outside this chamber can be seen the date 1957, though it cannot be seen from the start elevator, but can at the end one.

Despite the original entrance of the chamber being condemned, Chell starts testing in the proper place, and is met with the following message:

This Test Chamber involves using a Repulsion Gel dispenser to portal the gel in the needed places, then make a long jump to the exit. As the first Test Chamber is destroyed, the test is already over, and Chell proceeds to Sphere 03, before hearing the following:

1958: Enrichment Sphere 03
This Sphere starts with the following message:

Test Chamber 27
Outside the first Test Chamber (numbered "27" for some reason) can be seen the building date 1958. Inside, the test involves precise timing, as water brought through a Conversion Gel pipe makes the Repulsion Gel go away, preventing the Test Subject to jump on it.

In the next room, the following message is heard:

On the wall can also be seen a sign asking Test Subjects to not listen in case a future them tries to warn them about the test. However no trace amount of time travel is seen at any time.

The next area is set above Test Chamber 27, and the Repulsion Gel dispenser must be used to reach the next chamber. Nearby is a safety sign reminding that accidents hurt "you" (you will be hurt), "coworkers" (don't endanger others), "the company" (replacements are costly), and "science" (investigations impede progress).

Test Chamber 28
When reaching the catwalks below Test Chamber 28, the following message is heard:

Test Chamber 28 was also built in 1958. Inside can be found a Cube in a large glass case, which must be broken after the Cube is covered in Repulsion Gel and starts bouncing everywhere. After being released, it must be caught and washed to be used on a button that will trigger the exit platform, then covered in gel again to release the platform.

Before the exit elevator, the following message, in which Johnson gets angry, is heard:

Elevator access
Right after leaving the Sphere elevator, the following message is heard, concluding the test series performed in the 1950s:

Four Spheres can be seen from here: the two last from the 1950s, and the two from the 1970s.

The access to the Main Lift follows, with a small lounge in the same style as that of the Testing Lounge featured at the bottom of the shaft, with another portrait of a brisk Cave Johnson, as well as a sign thanking Test Subjects for their participation. Inside the shaft can be seen that the area is at a 4000m depth.

1970s levels: Propulsion Gel
The Mobility Gels tested in this level era are the Repulsion Gel and the newly introduced Propulsion Gel.

Of note is that the timeline jumps from the late 1950s to the early 1970s, as the Shaft was condemned in 1961 to be reopen in the early 1970s.

1971: Pump Station Beta
As the Main Lift is disabled, Chell must portal herself from the 1950s exit area to the next set of Sphere, starting with Pump Station Beta, built in 1971, and pumping Propulsion Gel added to the Repulsion Gel.

Inside Pump Station Beta, Chell must portal herself to the top of the deep room and powers back the two pumps in rooms with a typical 70s style, with wooden walls and an orange tiled floor, as well as typical white and orange 70s objects.

1971: Entrance Way
Reaching the area where Test Subjects would arrive from the Main Lift in the 1970s, Chell can hear the original welcome message:

A large faded orange metal logo shows that at that time the "Aperture Science Innovators" brand had been changed to the current "Aperture Laboratories", what will become the Aperture later being around the platform of the elevator leading to Enrichment Sphere 04, located behind. The Main Lift access is still condemned, and inside can be seen a 3975m depth. The wall left of the elevator access is very damaged, and the catwalk originally tied to it was damaged as well, preventing from reach an office above. Chell portals herself to that office, and accesses a corridor from a door located behind a large computer.

Borealis’ drydock


In the corridor can be found four doors leading to vitrified Test Chambers, one of them having been blasted on the floor. Each of the three shut doors has an interphone, which when powered will give the following pre-recorded messages by Johnson about what tests they involve, reminiscent of what is seen at the bottom of the shaft:

The opened door ("vitrified" can be seen on it by noclipping) leads to a large and empty drydock that used to house the Borealis before the experiment performed there made it disappear. A barrier prevents from going into the drydock itself, and several life preservers bearing the ship's name are scattered on the floor.

Test Subject Waiting Area
Back into the welcome area, below the office leading to the Borealis' drydock is a two-story building. The ground floor is for Test Subject reception. The entrance hall features the portrait of an older Cave Johnson from the 1970s, now with sideburns. The Test Subject Waiting Area follows, in which Test Subjects had to take a numbered waiting ticket before being called for testing. Two images on the wall also promote the promised $60. The floor also houses two offices with dry plants. One features a poster asking Aperture employees to alert their supervisor if they see the following: OSHA Inspector, Dept of Energy Inspector, GAO accountant, undercover police officer, Nuclear Regulatory Commissioner, FEMA Coordinator, ordinary police officer, journalist, Public Works Inspector, MSHA Mine Inspector, ATF / FBI / US Marshal.

Control Room
The Control Room room above is not connected to the waiting area, and was presumably access from catwalk stairs now missing. There are further desks, and in a small room the Elevator Control button that operates the platform leading to the Sphere 04's elevator.

There Chell reunites with GLaDOS, being pecked by the bird in its nest after the latter grabbed her in the Tartaros area, showing it was able somehow to follow Chell inside the shaft. GLaDOS asks Chell to kill the bird as she is "good at murder", but it escapes when she approaches. GLaDOS tells Chell how important it is that Wheatley is disconnected. The AI then bargains to be taken with Chell, since she states she must replace Wheatley before he completely destroys the facility. Chell sticks one of her ASHPD's appendages into the potato, activating the Elevator Control button hidden in the nest. Shortly after, GLaDOS "passes out". As Chell cannot activate the button and be on the platform at the same time, she portals herself to it, going again through the Aperture logo before reaching her destination through momentum.

1972: Enrichment Sphere 04
This starts the seventh chapter, The Reunion, and tests with both the Repulsion and Propulsion Gels.

At the start, the following message is heard:

GLaDOS oddly reacts to the message, answering to Johnson the same words as that of Caroline.

Test Chamber 01
This chamber, dated 1972, requires coupling the Propulsion Gel with a springboard.

On the catwalks between Test Chamber 01 and 02, Chell has the ability to portal herself to Test Chamber 01's observation room, where a portrait of Cave and Caroline is found. To this, GLaDOS comments "Those people, in the portrait. They look so familiar...". In the room, two posters previously seen in the Test Subject Waiting Area are found.

Test Chamber 02
In this chamber, also dated 1972, the Propulsion Gel must be combined with the Repulsion Gel. At the end of the chamber, the following message is heard:

The part of the tape that cuts out says "take the world".

GLaDOS comments she swears she knows the voice.

Test Chamber 05
At the start of the sole chamber found in Sphere 05, dated 1976, the following message is heard:

The chamber requires the Propulsion Gel must be combined with the Repulsion Gel through a set of different platforms, combined with a Cube and a springboard. This is very reminiscent to the later levels of Tag: The Power of Paint, from which the Mobility Gels were inspired.

At the end of the Sphere, the following message is heard:

1978: Elevator access
This section, dated 1978, marks the end of the 1970s levels. Above, the Test Subject Waiting Area for the Conversion Gel can be seen. On the catwalk out of Sphere 05, the following message is heard:

The catwalk leads to a L-shaped corridor ending at the Main Lift access. Near the first corner, a sign reads "Thank you for not loitering longer than 20 minutes". Left of the elevator access, and facing three chairs, is a small booth in which a chair, a desk, a phone and a portable TV can be found. On its side, the following sign reads "All forms must be filled out legibly and completely before eligible to receive payment of $60". The elevator access is condemned, and on it can be found the same "out of service" sign found in the 1950s Entrance Way.

Chell portals herself on catwalks above, and beyond a heavy door she is back in the shaft. Catwalks used to lead to Pump Station Gamma, but as they are destroyed, Chell portals herself beyond the gap.

1980s levels: Conversion Gel
The Mobility Gel tested in this level era is the Conversion Gel.

1982: Pump Station Gamma
Scaffoldings can be seen outside and above the Pump Station, dated 1982, suggesting some elements were never completed.

Inside the station GLaDOS wonders who might be this Caroline, if she might have kill her. She suddenly stops, troubled, and tells Chell she is doing great job, then stops speaking after saying she needs to think.

The Pump Station is made of three pumps, one for each Mobility Gel. The 1980s are conveyed through white-colored devices, and a white-colored wall decorated with a light-blue colored line at the top. The pumps are leaking and Chell uses it to her advantage to portal herself to the upper level of the Pump Station as the catwalks leading to it are gone, and avoids eight deadly pistons in the process. Before exiting the station, a poster can be seen, promoting robot workers replacing human employees and encouraging the latter to volunteer for testing. It starts with the sentence "Karla the complainer says... ‘My new boss is a robot!’". Right after, "But did you know?" introduces the three following sentences: "Robots are SMARTER than you", "Robots work HARDER than you", "Robots are BETTER than you" Under is a picture of "Karla the complainer" sitting at a desk, with standing in front of her her "new boss", a robot wearing a tie and holding a cup. "Volunteer for testing today" is written under the image. Back into the shaft, the bird can be found flying off from the catwalk, making GLaDOS scream. Spheres 05, 06 and 07 can be seen. The catwalk would lead to the next Test Subject Waiting Area, and as usual, as it is destroyed, Chell portals herself beyond the gap by using spilled Propulsion Gel inside the Pump Station.

During this era, the current "Aperture Laboratories" was introduced. The Portal 2 game files reveal that a model for a large and damaged metal version of that logo variant was to be seen somewhere, in a similar fashion to that of the previous era levels, but it was ultimately scrapped.

Combatation Testing Area
Under the Test Subject Waiting Area can be found a small platform with a door leading to a vitrified "Combatation Testing Area" with a warning saying "Remain still if you are targeted".

1981: Test Subject Waiting Area
Above the Waiting Area building can be found two other inaccessible buildings. Upon entering the Waiting Area, dated 1981, the following message is heard, in which Johnson appears to be ill:

Inside, a small sign "Enrich yourself today - volunteer for testing" is found. The area is dimly-lit with a cold light. The overall colors are greyish-blue and white, and is closer in design to the offices of the modern Enrichment Center. Another sign, titled "Know your paradoxes (!) in the event of a rogue AI", is found. It advises employees to "1. Stand Still, 2. Remain calm, 3. Scream ‘This statement is false! New mission: Refuse this mission! Does a set of all sets contain itself?’".

The Waiting Area, below, is accessed through a smashed window. It appears Test Subjects would come through a door smaller than usual, and the direct access to the Main Lift is not seen. Next is the last portrait of Cave Johnson, appearing older and ill. Left is a door leading the proper Waiting Area, right is a door to a small office where a button opening the door to the testing area is found. There the "Karla the complainer" poster is seen again, along with another similar poster with "Remember... robots don't sleep", followed by "They can test and do your job" and the picture of a robot worker testing and sorting paperwork very fast behind a desk at the same time, finally followed by the words "Volunteer for testing today". Inside the Waiting Area can be found a poster titled "Aperture Science - Let's work together", with a robot worker and human employee wearing labcoats and walking hand in hand in front of a sunset, the sun being Aperture's aperture logo. The room contains several chairs, and a projector directed toward a white screen, on which motivational videos were probably played. A catwalk leads to Sphere 06, and a warning sign reads: "Please do NOT test if: - You are allergic to lunar sediment and/or starch; - You have fulfilled your monthly self-election quota; - You are confident enough in your work performance to unvolunteer from the test self-election process". There is no fizzler before the elevator; an unseen one is used instead in the elevator tube.

1982 - 1986: Enrichment Sphere 06
Built from 1982 to 1986, it consists of a single Test Chamber, filling half of the sphere, though the numbers 01 and 02 are seen on two columns. It is the only Sphere testing the Conversion Gel, which is not used with the conjunction of any other gel. The ceiling is uncompleted, allowing to see Sphere 07 above.

After Chell completes the test, the following message is heard, in which Johnson has his now infamous rant about lemons (to which GLaDOS reacts enthusiastically), and putting someone's brain into a computer, another hint that Caroline's mind was used to create GLaDOS:

Enrichment Sphere 07
The seventh and last Enrichment Sphere cannot be visited and appears to be not connected to any part of the shaft. It is not present on the screens of the three machines operating the Pump Stations, suggesting it was never used in Mobility Gel testing.

1982: Elevator access
The elevator access, dated 1982, starts with a sign thanking employees for volunteering, followed by the words "Please return to your desk and await further opportunities", then a small booth, then a small door to the Main Lift, which is now accessible. The depth is now 3000 m. Since the elevator is out of order, Chell portals herself up the shaft. The elevator is stuck at around 2912 m. Chell finally leaves the elevator shaft through a maintenance door, located slightly above 2900 m, to get back into Test Shaft 09, now at its uppermost level, above Sphere 07. After GLaDOS attempts to cheer Chell up, the latter goes through a set of several platforms by using leaking pipes of each Mobility Gel, to finally arrive in the main Gel Pump Station through a maintenance shaft.

Gel Pump Station
The Gel Pump Station pumps Mobility Gels from below into the modern facility. Larger than the three previous ones, it also contains Transition Seal 02, the other hatch sealing off access to the shaft, and leading to the modern facility. The hatch can be opened with a Hatch Override button located in a booth to which Chell portals herself. Inside, the "paradoxes" sign is seen again, and GLaDOS suggests they could use paradoxes to defeat Wheatley.

Upon opening Transition Seal 02, the Mobility Gel connection to the modern facility is restored, and a platform lowers to receive Chell and GLaDOS. While ascending, the A.I. talks again about her plan to overthrown Wheatley.

Then they find herselves right under the modern facility, which appears to rest not only on giant numbered pillars but on giant numbered springs as well, reminiscent of the real-world NORAD facility. Upon going back into the modern center, they come across the 1961 vitrification order from that side. After passing through a modern Emancipation Grill, they take a modern elevator bringing them back into the modern facility.

Upon leaving the elevator, the duo quickly reunites with Wheatley through his screens, and discover the newly built "boxes with legs", the Frankenturrets, starting the game's eighth chapter, ''The Itch ''.

Behind the scenes

 * Since this article is very long, many BTS facts have been placed near their related subjects for better reading.


 * The Enrichment Shafts are what remains of the canceled game F-STOP, which originally was to be a prequel to Portal 2 set during Cave Johnson's era, hence the old-fashioned design of the area. It was not to feature portals, and Johnson was to be a protagonist later turning antagonist, a role adapted for Wheatley in the final game.


 * As a "timeline" level, Test Shaft 09 provides many new dates and events pertaining to Aperture's history, many of which significantly alter the original Aperture timeline revealed prior Portal 2’s release on ApertureScience.com.


 * The last sign seen during Chell and GLaDOS' fall to Test Shaft 09 indicates 4375 m; as seen when Chell wakes up, the very bottom is lower than that. However, when adding up the different heights featured in Test Shaft 09 (the depth on top of the 6th sphere being 2975 m, a sphere having ~87 m in height, the first sphere having around a sphere's height under it, having ~50 m between the 50s and 70s spheres, and ~25 m between the 70s and 80s), a total of ~3660 m only is found; thus one of the two depths is incorrect.


 * The game files reveal several signs not appearing in-game, as well as codenames to be used for each sphere, each time starting with a NATO phonetic alphabet code word. The names are, in sphere order (given by the texture file names "underground_sphere_00 # "): "Whiskey-Hubble", "Bravo Volta", "Oscar Darwin", "Tango Franklin", "Juliet Planck", "Hotel Kepler", and "November Brahe".

List of appearances

 * PotatoFoolsDay ARG
 * Portal 2
 * The Final Hours of Portal 2