In this level, you will be reintroduced to the Flood who have managed to infest parts of the station. Save for a brief Banshee excursion, you'll be doing this one entirely on foot. The level begins with a series of three unskippable battles, where you are beset on all sides by infection, combat, and carrier forms. Thereafter, you'll encounter a number of heretics fighting a rear guard action in hopes that their leader will escape. In contrast to the first part of the level, your progress from this point onward is relatively fast-paced, and includes some battles that can be outright avoided with proper use of active camouflage. Finally, it culminates with Halo 2's very first boss battle.