After exiting the Noontech Diagnostic Machine, Isaac encounters the Ubermorph, a "pure" Necromorph which has the ability to regenerate its limbs. Isaac has to disable it for long enough time to hack the control panel of a door and get out of the room. After walking through a corridor, he enters a room where he has to use the body of a man as an ID to get past the room, at the same time being attacked by the Ubermorph and other Necromorphs (Enhanced Slashers and Pukers). Isaac finds himself being followed by the Ubermorph through most of the chapter, while simultaneously fighting his way through small, narrow corridors. After being attacked by Enhanced Slashers, Swarmers and the Ubermorph, Isaac finds himself in the process of trying to get to an elevator which takes him down to a small room where he is attacked by more Necromorphs; which he can exit after hitting a circuit board which was jamming the door. Next, Isaac proceeds into a Zero-Gravity chamber, after which the Ubermorph doesn't appear until the chapter after this stage. Isaac floats through a couple of hazards and a Nest which he finds at the end of the Zero-Gravity room. After deactivating the gravity and exiting the Zero-G room, he enters a passage where he finds a Power Node locked room. Exiting the passage, Isaac enters a chamber which has a Store, a Bench and a door at the other end of the room which, upon proceeding through, he begins the final chapter.
There is a glitch where after you beat the first hacking mini-game, if the Ubermorph hits you just after completing the third set, the door will be unlocked and the animation will play but not open. It then leaves you trapped inside.
Towards the end of this Chapter, there is a glitch that allows the player to collect an infinite amount of Power Nodes and Credits.
The Ubermorph can be glimpsed in Chapter 13, but this chapter is the first time Isaac actually must battle the Ubermorph.