Exiting out of the dam pipe, Shepard finds himself on a river path where several HECU marines have been hiding from the Black Ops. With Shepard's help, the new squad fights the Black Ops back along the river path towards a complex being guarded by Black Ops controlled heavy artillery on its roof. Shepard clears out the complex of the Black Ops, and locates another military radio where he hears a soldier calling for back-up as they're pinned down by the Black Ops in the nearby bunker. Unfortunately, the Black Ops come storming out of said bunker having killed the HECU soldiers before Shepard could rescue them.
Shepard enters the bunker, and goes through a pipe vent, which leads him up to the roof of the complex where the heavy artillery was set up. He takes control of the heavy artillery to blow open the door of the nearby Ordinance Storage Facility, and fights any alien that comes out of it. Shepard's squad enter the storage facility where the war between Black Ops and Race X has become intense to the point of the Black Ops needing to bring in a AH-64 Apache helicopter. Shepard fights his way into the storage area's parking garage where he locates a surviving Black Mesa security guard hiding in the vents. The guard warns Shepard how he overheard the Black Ops talking that they might be planning to blow up the facility with some sort of bomb. Sure enough, the Black Ops have activated the thermonuclear warhead that they picked up back in "Friendly Fire" within the parking garage.
Shepard comes to a locked door that leads to the Level 4 Storage Unit. The Black Mesa security guard hiding on the other side tells Shepard that he's not opening the door until the bomb is shut down. The corporal then fights through the Black Ops guarding the bomb, and succeeds in deactivating it. Returning to the locked door, the guard opens it for Shepard, who then warns the corporal that the only way of escaping the facility is through the Level 4 Storage Unit that the Black Ops were using as their staging point before the arrival of the aliens. Before moving on, Shepard sees through a window that the G-Man is reactivating the bomb, and has blocked the path back to keep Shepard from stopping him. As a result, Shepard is left with taking the elevator down to the Black Ops fortified Level 4 Storage Unit in the hopes of escaping Black Mesa before the nuclear bomb goes off.
This Chapter contains examples of:
- Black Helicopter: Amongst the reinforcements that the Black Ops call in to hold back the Race X Invasion is a black AH-64 Apache helicopter. Shephard must destroy it in order to advance, as it can and will open fire on him once the helicopter defeats the Race X aliens in the area.
- Evil Plan: The Black Ops' evil plan is to blow up Black Mesa with a nuclear bomb. Shepard at first looked like he put a stop to the plan only for it to turn out that the G-man has reactivated the bomb shortly after the corporal left.
- Plot Hole: A couple of Vortigaunts get teleported
at one point during this chapter, which shouldn't be possible given that the Nihilanth is dead by this point. Apparently that was an error on a mapper's part, and those two Vortigaunts were supposed to be Shock Troopers. - The Reveal: While it was hinted at back in "Friendly Fire", the overall plan of the Black Ops is revealed here.
- Unique Enemy: This is the only level that the Black Ops Apache is fought in.
