Sector D Administration

"Hey, what the hell are you down doing here? Get topside! I hear troops are coming in to save us!"

- Security guard

Sector D Administration is one of the seven main sectors of the Black Mesa Research Facility. Appearing only in Half-Life, it is covered by three chapters: Office Complex, "We've Got Hostiles" and Blast Pit. It is connected to the Yellow Line of the Black Mesa Transit System.

Administration Center
Covering the chapter Office Complex, that section is accessed from Sector B by an elevator. It is mainly a large underground complex where the bureaucratic aspects of Black Mesa's upkeep take place, along with some limited research.

Executive Lounge
On the right in the corridor after the Sector B elevator, this section consists of a dimly-lit small lounge with sofas and vending machines, one of them filled with cockroaches. Barnacles are also hidden in the false ceiling, and the two scientists hiding there soon become their victims.

Going left in the corridor after the Sector B elevator leads to the Administration Offices, the High Security Storage Facility and the Cafeteria. The sign indicating the main sections also feature the words "Work harder, not smarter" under the section names.

An explosion caused damage in the corridor, partially damaging the ground and causing electric cable to hang from the false ceiling. To proceed further, Gordon must turn off the power from the Executive Lounge.

As the next door is closed, the nearby window must but broken to enter. The first office to be found is the office D-AL 101, belonging to Dr. Newell. At the time of the Black Mesa Incident, it is flooded and electricity is running through the water.

Nearby are also two storage rooms. One of them, a small one, has a Zombie inside. The other, further and larger, is behind a fence where a security guard can be found. As a Zombie is arriving behind, it has to be killed as fast as possible, as if the guard is killed the access to the storage room, full of supplies, will not be granted.

Since the doors granting access to the rest of the Sector are closed, Freeman must use the vent in Newell's office to proceed, involving a small puzzle to turn off the power.

High Security Storage Facility (small)
After some other puzzle vents to go around the closed doors, a small High Security Storage Facility is reached. A medium room filled with crates, it is protected by a Ceiling Turret that kills a scientist and the many Headcrabs found there. Below the turret is a switch that turns it off.

Administration Offices
The Administration Offices are split into three main sections, with the Cafeteria in the middle.

Admin 1
In the first office, D-AL 101, two scientists are found trying to escape through a vent, to be killed inside shortly after. D-AL 102 consists of two rooms. Another office with a calendar can be found, as well as a small lounge that has a Maintenance Access hidden in the false ceiling leading to the Ceiling Turret located beyond, in the stairs. Stairs a several corridors will lead to the cafeteria.

Admin 2
Consists of corridors, the Cafeteria and D-AL 101, a small office with supplies only accessed through vent, with its door leading to the Cafeteria.

The Cafeteria consists of a large and mostly empty room where several scientists lying dead in their blood on tables. A door leads to stairs leading to the Admin 3 section, but it cannot be opened when Freeman gets there. A balcony above is also linked to the top of stairs leading to the Admin 3.

A barricaded corridor will lead to another, small room with coffee machines, one of them with "Valve" written on it. What follows is a large walk-in freezer with meat hanged to the ceiling and Bullsquids fighting Headcrabs. Again, Freeman will be able to reach Admin 3 through vents, after using a crate conveyor in the freezer.

Admin 3
After going up the stairs leading to Admin 3, the G-Man can be seen behind a closed door on the balcony above the Cafeteria.

What is seen of Admin 3 is the office of Dr. Van Buren, another dark office linked to it, and a glass bridge going over the corridor. After that is an elevator leading to a bigger High Security Storage Facility. It is jammed when Freeman gets on the spot, and scientist is hanging to the ladder hanging from it. As Freeman climbs inside the shaft towards the elevator, the scientist falls to his death. Afterwards Freeman gets inside the elevator, and its doors open to the High Security Storage Facility.

Facility 1
Covering the chapter "We've Got Hostiles", the High Security Storage Facility is a large semi-subterranean warehouse made of interlocking Storage Areas located on the surface, built right above the Administration Offices. As the HECU has just invaded the facility, many Sentry Guns and Laser Tripmines are installed among the facility, killing both scientists and Xen creatures. Most areas are separated with heavy fire doors that will close when their emergency button is pressed. The HECU are also put many metal crates here and there to hinder anyone's progression.

After leaving the Administration Offices elevator, the blast door to Silo D can be found, with a security office in front of it, containing the switch to open the door. This is where Freeman will leave the area for Silo D, when he can reach the security office through a vent.

Storage Area 1
Contains Sentry Guns, crates and teleporting Headcrabs.

Storage Area 2
In the first room more Sentry Guns are two scientists who are soon killed. Water is leaking from a pipe, making the ground slippery. An open elevator shaft can also be found. The slippery ground adds to the difficulty of avoid to fall into the elevator shaft and defeating the Sentry Guns at the same time.

In the second room, the G-Man is seen again on a catwalk. A blast door leads to Storage Area 3, but is is shut.

Storage Area 3
After reaching that room with G-Man's catwalk, a scientist runs to the first HECU soldier to be seen; the latter shoots on sight, showing Freeman the army is not there for a rescue. An elevator goes up to another Storage Facility.

Facility 2
This area located above the first Storage Facility is reached by an elevator.

Storage Area 1
There the massacre actually starts. HECU soldiers continue firing at scientists. A corridor then leads to Storage Area 2 or Storage Area 3.

Storage Area 2
This is a large room filled with crates and Barnacles. The massacre continues.

Storage Area 3
The lower section of that area has a conveyor belt used by Freeman to reach Area 2 from Area 1. He then goes back to Area 3 from a bridge located above, then leaves through the Surface Access elevator that leads to an outdoor area upstairs. There more HECU troops and an Osprey are waiting for Freeman.

Central Ventilation
Freeman must travel through the Central Ventilation, then the vents that go around the previously visited Storage Facilities, to finally reach the office with the Silo D access door button. There a scientist tells him to seek for help at the Lambda Complex.

Silo D
Covering the chapter "Blast Pit", the Silo D, located in the lower levels of Sector D, houses the Experimental Propulsion Labs or the Rocket Test Labs, used for testing rocket engines. This sector actually consists of three Prop Lab Silos. It is connected to the High Security Storage Facility by a large elevator (where a Bullsquid is killing Headcrabs from a long distance), then an old decommissioned rail system filled with Houndeyes and Bullsquids. After a few sections filled with pipes, more Bullsquids and radioactive waste, an elevator located outside Silo D itself brings Freeman inside. In the middle of Silo D is Silo D-01. The two other Silos are directly connected to the main Silo D, but can only be accessed through Silo D-01.

Silo D-01 - Engine Testing
Of all three Silo Ds, this red-coded Silo is the largest and the most important, and where the engines are actually tested. There three Tentacles can be found, hindering Gordon's journey. Defeating them is the main purpose of the chapter Blast Pit, as the Black Mesa employees present there have failed so far. There Freeman witnesses a scientist being killed by the Tentacle, then a bold security guard being killed after shooting at them. Then Gordon carefully goes through the Silo to reach the two other Silos where he activates the power and restores the oxygen and the fuel's arrival to Silo D-01. When going back from the Silos, he presses the Test Fire button, launching the rocket engine and destroying the Tentacles.

Silo D-02 - Power Facility
The green-coded Silo, it is used for Silo D-01's power. It is accessed from the lowest door inside Silo D-01. After leaving Silo D-01, an elevator leads to lower levels, and it fails while Gordon rides it, almost killing him in its fall in the toxic waste below. There Freeman comes across a scientist that tells him Smithers attempted to start up the generator but never came back. When reaching the actual Silo D-02, one of the two moving platforms allowing easy movement along the Silo is malfunctioning, going from both sides very vast, and must be avoided to proceed to the generator above. After finding Smithers stating he will not move, Freeman starts up the generator and heads back to Silo D-01, after a small puzzle to avoid the electrified water in the corridor above (now that the power is restored, current is now going through the water leaking from a pipe above).

Silo D-03 - Wind Tunnel
The yellow-coded Silo, it contains a huge propeller and is accessed from the upper door inside Silo D-01. The nearby Fuel Room contains the fuel and oxygen reserves provided for the Silo D-01 engines. When Freeman reaches Silo D-03, the Fuel Room cannot be accessed, and he has to go through the Silo itself to turn on the propeller, "fly" to the top of the Silo, then reach the Fuel Room through vents, before heading back to Silo D-01. As activating the fuel and oxygen in the Fuel Room after reaching it by noclipping works without activating the propeller, its actual purpose is obscure.

Behind the scenes

 * Originally, the Silo D chapter did not involve Tentacles, as suggested by Ted Backman in his concept art images. The main purpose of the chapter was rather to open the top of the Silo and leave through there. This was to be achieved by turning keys in the Launch Key Room located elsewhere, involving several puzzles between the two sections.


 * Another image by Backman shows that the catwalks found in the area around Silo D-01 were originally to be attached to the walls by cables, which was simplified in the final version.


 * Chuck Jones designed the Tentacle and the Silo D scene where the creature grabs the scientist and hauls him screaming from Silo D-01's control room. According to John Guthrie, no one at Valve was prepared for anything like this scene. When they saw the effect it had on gamers in sneak previews, they knew they had made the right decision to put animated sequences directly into the game rather than setting them apart in cut scenes.

Trivia
The texture used in the false ceiling contains the word "Valve". It is also used in the Half-Life expansions.

List of appearances

 * Half-Life: Day One
 * Half-Life
 * Half-Life: Blue Shift
 * Half-Life 2: Raising the Bar