Half-Life 2: Episode Two

Half-Life 2: Episode Two is the second installment in a trilogy of episodes for the 2004 first-person shooter computer game Half-Life 2, from Valve Corporation.

Continuing with Valve's method of orienting each episode around a particular theme or set of technologies, Episode Two focuses on expansive environments, travel, and large, nonlinear battles. Following the closing events of Episode One, it sees Gordon Freeman and the series' other major characters moving away from City 17 to the surrounding wilderness.

The first two episodes of Half-Life 2 were developed concurrently by separate teams. Episode Two was originally intended to be released in two different packages: the "Black Box" – which was to ship for the PC only, and was to contain Episode Two, Portal and Team Fortress 2 – and the "Orange Box" – which was released for the PC, the XBOX 360 and the PS3, and contains all the Black Box games in addition to Half-Life 2 and Episode One. The Orange Box is now available at retail stores and on Valve's Steam content-delivery system, however, the Black Box was cancelled. Instead Valve introduced a gift feature to enable those who already own Half-Life 2 and/or Episode One to give the extra copies they buy in the Orange Box away as gifts. It is possible to buy one or all of the Black Box games seperately on Steam, but even if you already own Half-Life 2 and Episode One, the Orange Box is still cheaper than buying all three games individually.

Plot summary
Continuing the plot of Half-Life 2 and Episode One, Episode Two consists of seven chapters telling the story of Gordon Freeman and Alyx Vance's journey through the White Forest to a large Resistance base named after the forest. After the destruction of the Citadel, the Combine are working to open a massive superportal to call for reinforcements. Combine Advisor pods have been scattered throughout the region. The destruction of the Citadel, as explained by Dr. Kleiner's broadcast in Episode One, has inflicted a portal and communications blackout on Earth-stationed Combine forces, leaving them isolated and disorganized. A crucial part of the plot is the transmission packet which the Combine sacrificed the Citadel to send, a copy of which Alyx and Gordon stole before making their escape. It contains information relating to the location of the Combine homeworld and allows the creation of the superportal to be controlled from the "other side". This information has to be delivered to White Forest so that the Resistance can use it to shut down the superportal and prevent an even greater Combine invasion.

After Gordon and Alyx climb out of the wreckage of the train they used to escape City 17, they make their way to White Forest. Pausing briefly to view the smoldering ruins of City 17 in the distance and the beginnings of the superportal originating at the base of the destroyed Citadel. Shortly afterwards a portal storm, which seems to originate at the Citadel ruins, sweeps the area, destroying the already critically damaged rail bridge nearby. At an abandoned mine, Alyx is gravely wounded by a Hunter while Gordon is trapped under fallen rubble. They are discovered by a Vortigaunt, who leads them to a mine where they get separated and Gordon must travel through the mine to the underground Resistance base, which is located at the center of an Antlion colony. The Vortigaunts there have the power to heal Alyx; however, Gordon must accompany the Vortigaunt into the Antlion colony to recover larval extract necessary for the healing ritual.

Once the extract is retrieved and the healing process begun, the G-Man contacts Gordon while the Vortigaunts are occupied. He hints at Alyx's importance to his own long-term plans, revealing that he had preserved Alyx's life at Black Mesa despite objections from unnamed others ("I have learned to ignore such... naysayers when quelling them is... out of the question."). The G-Man then instructs an unconscious Alyx to tell her father to "prepare for unforeseen consequences." (Unforeseen Consequences is the title of the third chapter in the original Half-Life, which takes place right after the resonance cascade occurred.)

After Alyx has recovered, she and Gordon proceed to the surface. There they see that a large group of Combine forces in the distance is moving towards White Forest. They acquire a working car from a Rebel base ravaged by Headcrabs.

Having acquired transportation, they proceed at top speed, slowed down by multiple Combine ambushes. They also encounter an encapsulated Combine Advisor, which Alyx attempts to kill by damaging its life support system. The Advisor awakens and demonstrates its telekinetic powers, pinning Alyx and Gordon to a wall. It appears unfamiliar with its environment, as it crushes a barrel and stabs a dead rebel with a tentacle-like tongue before an explosion wounds it, forcing it to flee. Despite repeated attacks and a vehicle breakdown, Gordon and Alyx continue to proceed.

Arriving at White Forest, Alyx and Gordon reunite with Dog, Isaac Kleiner, and Eli Vance. The player is also introduced to Dr. Arne Magnusson, another former Black Mesa scientist who is egotistical, verbose, and authoritarian. The team of scientists is preparing a special rocket, which they plan to use in conjunction with the satellite array launched during the events of Half-Life to close the Combine superportal. However, nearly as soon as they have arrived, the large force of Combine seen earlier in the game, attack the base, complete with Striders and Hunters. Using Dr. Arne Magnussons newly created Strider Buster, Gordon is able to hold off the attack and prevent the Combine from destroying the rocket. The rocket is then successfully launched, preventing the Combine from opening another superportal to their homeworld. Sadly, as Gordon and Alyx prepare to depart to search for Dr. Judith Mossman, Advisors attack the helicopter hanger and kill Eli Vance with the chance that they have obtained all information of the resistance from Eli, before Dog scares them off.

Chapters

 * Chapter 1: To The White Forest
 * Chapter 2: This Vortal Coil
 * Chapter 3: Freeman Pontifex
 * Chapter 4: Riding Shotgun
 * Chapter 5: Under the Radar
 * Chapter 6: Our Mutual Fiend
 * Chapter 7: T-Minus One

Allies

 * Alyx Vance
 * Vortigaunts
 * Griggs
 * Sheckley
 * Sweepy
 * Resistance Fighters
 * Eli Vance
 * Isaac Kleiner
 * Arne Magnusson
 * Lamarr
 * Uriah

Xenian: Headcrab

 * Headcrab
 * Zombie
 * Fast Headcrab
 * Fast Zombie
 * Poison Headcrab
 * Poison Zombie
 * Zombine (Combine Zombie)

Xenian: Barnacle

 * Barnacle

Xenian: Antlion

 * Antlion
 * Antlion Grub
 * Antlion Worker
 * Antlion Guard
 * Antlion Guardian

Combine

 * Overwatch Soldier
 * Overwatch Elite
 * Shotgun Soldier
 * City Scanner
 * Manhack
 * Hunter-Chopper
 * Combine Dropship
 * Combine Gunship
 * Hunter
 * Strider

Gameplay
As was suggested in press releases, Episode Two generally concentrates on more expansive locales as compared to the claustrophobic Episode One, particularly in its latter chapters, although it ends similarly to Episode One with a pitched battle in a fixed environment. The Muscle Car chapters are very reminiscent of the Highway 17 Chapter of Half-Life 2. Episode Two is longer than Episode One, approximately two thirds the length of Half-Life 2.

Episode Two introduces two new enemies: the Antlion Worker and the Combine Hunter synth. As discussed in the commentary of the game, both display new, sophisticated types of A.I.: the Antlion Workers' in their standoffish approach, and the Hunters' intelligent flanking and flushing out maneuveurs. With the Hunters in particular, with their resistance to conventional attacks, their deadly close combat moves and their weakness to thrown objects, the developers hoped to encourage players to interact with the game environment more closely, and try different tactics each time.

The game also introduced Antlion Grubs and Antlion Guardians, the behaviour of whom make the first chapters of the game different from anything yet experienced in the Half-Life games, and were also used to explain the inner workings of Antlion society. The game also gradually reveals the characteristics of the sinister Combine Advisors, and they play a much more central role to the Episode than in previous installments.

Although no new weapons as such are introduced, the Strider Buster, used to defend White Forest against a Combine offensive, is crucial to the last stages of the game. Valve stated before the release that they were not interested in creating new weapons, as they were more interested in exploring every dimension of the Gravity Gun, the Strider Buster being the outcome of this. This decision came in spite of the fact that the lack of new weaponry in Episode One was one of its most criticised aspects.

Technical Information
Running on the so-called "Source 2007" version of the Source engine, Episode Two comes with numerous technical improvements and new features as well as those introduced in Episode One (such as Phong shading and HDR lighting). Some of the more important technical improvements seen in Episode Two are:


 * Cinematic physics - where real-time physics calculations are mixed with keyframe animation targets to create large-scale physics events. The bridge collapse at the very beginning of Episode Two is one example, as are the collapsing buildings in the final battle.
 * Motion blur
 * Dynamic lighting and shadowing 2
 * Soft-Particle system
 * Dual and quad-core CPU optimizations

In addition to the widely-publicised new features, there are also a number of less noticable but nonetheless significant improvements. Lighting effects have been improved even further since Episode One, with the bloom effects toned down slightly to give the game a slightly less surreal look. Many character models have been improved upon once more, while the A.I. is slightly more sophisticated, most noticeably in the behaviour of the new enemy - the Hunter synth. Most textures have been improved, special shaders have been applied to many characters and objects and almost everything is bump mapped.

Episode Two Soundtrack

 * Extinction Event Horizon - 2:03
 * Vortal Combat - 3:15
 * Nectarium - 1:47
 * Crawl Yard - 1:11
 * Hunting Party - 3:29
 * Shu'ulathoi - 2:36
 * Sector Sweep - 2:47
 * No One Rides For Free - 1:02
 * Eon Trap - 3:14
 * Inhuman Frequency - 1:49
 * Abandon In Place - 2:45
 * Last Legs - 2:07
 * Dark Interval - 1:33