"Well, it seems the dimensional breach is definitely transporting organic matter."
With Black Mesa in ruins and strange, dangerous creatures start popping into existence left and right. Gordon is tasked by the surviving scientists with heading to the surface to get help. Unfortunately, the tram has been destroyed, necessitating that Gordon find a different route through the facility by going through the Coolant Reserve sector that resides next to the Anomalous Materials lab. Along the way, Gordon comes into contact with the strange and hostile life forms, such as the Headcrabs, Headcrab Zombies, Houndeyes, Barnacles, Bullsquids, and Vortigaunts, which he's forced to start arming himself to survive.
This Chapter contains examples of:
- Alien Invasion: Of an atypical kind: the aliens are technically invading, but they are being teleported here against their own will as a result of the Cascade. And while they are quite hostile, they're not intelligent; most of them are simply wildlife lashing out in panic.
- Backtracking: The start of the level has the player going back up through the Anomalous Materials lab. Only now, the place is falling apart due to the resonance cascade.
- Body Horror: Introducing the headcrabs, small but aggressive aliens that attack by leaping onto the heads of human prey, latching on, and converting them into mindlessly vicious zombies. Worse, the zombies physical forms seem to mutate, such as their fingers extending into claws.
- Escort Mission: An optional one in the Coolant Reserve area is to escort a scientist to have him open up an office filled with supplies.
- Establishing Character Moment: The first time you see a headcrab, it is trapped inside an inescapable glass tube... yet still viciously trying to attack you.
- Foreshadowing: Very subtly. Gordon passes through the "Coolant Reserve Facility", implying that there's a reactor around here somewhere, despite Black Mesa being powered by a hydro-electric dam. This sets up the Lambda Reactor that powers the teleporters in Chapter 14.
- Helpless Window Death: A scientist can be seen fighting off headcrabs in an inaccessible office; he manages to squash one with a filling cabinet but another one jumps onto his head from behind and incapacitates him, and Gordon can only watch through the unbreakable windows.
- Loophole Abuse: It's possible to get the pistol earlier than you're supposed to from the surviving security guard by getting him killed. Usually, players themselves kill the guard.
- My God, What Have I Done?: One of the scientists you encounter on your way back from the test chamber is near catatonic in shock and horror after the resonance cascade and expresses his feelings thusly:Scientist: Why didn't they listen? I never thought I'd live to SEE a resonance cascade, let alone create one!
- Mysterious Watcher: The guy in the suit doesn't seem terribly worried about all the horrors running around. Nor do they seem to care about him.
- Optional Party Member: There's a surviving security guard that can help Gordon make his way through the Anomalous Materials lab back to its entrance lobby, which they're forced to split at a vent entrance.
- Shout-Out: The elevator is based on one
from AKIRA. - Sidetrack Bonus:
- If you return to the Anomalous Materials locker room, Gordon's locker will have some spare shield batteries in it. Another locker that was for a security guard named Guthrie will also be open that provides some spare ammo.
- It's possible to get back out to the Anomalous Materials Lab's tram station if you break the wall computer that controls the lab's entrance door. However, it's a dead end since the tram is gone. This side area is basically just for some spare ammo from the nearby dead security guard.
- In the Coolant Reserve, there's a side area with a locked office that you need to bring the nearby hiding scientist to in order to open it. This office is the first opportunity in the game to pick up some Hand Grenades.
- Slave Mooks: The Alien Slaves, as you can tell by their name and the metal collars they wear. The question is, who's enslaving them?
- To Serve Man: It's unclear about the Bullsquids, Houndeyes and Slaves, but Barnacles and Zombies seem to devour humans without hesitation.
- Video Game Setpiece: The electricity-wielding Alien Slaves make their debut when one of them teleports into a locked, metal closet, and proceeds to smash it's way out through the steel door.
- When All Else Fails, Go Right: Frequently throughout the chapter. In fact, it can get you some grenades.
