The primary enemies encountered in the chapter are Vortigaunts and Alien Grunts (as the HECU have now evacuated). The player also encounters a group of Black Ops Assassins in a storage room. A puzzle element is introduced as well: The teleportation labs harbor one-way portals (each leading to various locations in the Complex, as determined by a series of numbers and ports) that the player must use to progress, as most of the paths have been blocked off.
Near the end of the level the player is given a chance to fully restock on ammunition, health, and suit power, and is introduced to the Long Jump Module.
And that's the end of the main game - congratulations!
