Restock on the ammo boxes scattered around the broken down train. You'll also want to restore any lost health after the previous fight. Use the save point to record your progress and pick up the nearby Power Node.
You'll face off against a group of Packs. These are small child enemies that will attack you in groups. Use area attacks such as the Javelin or Line Gun to finish off these terrors.
In the next room a few enemies will appear on down the hall. Shoot out the window to suck them out into space. Next, fire at the switch above the door to close the shutters and save your own life. The next room contains a video explaining how to use Necromorph parts and Kinesis as a deadly weapon. Move to the next area and use the terminal to shut off the compactor. There is also a power Node near the machine.
Gracefully skim through the now inactive trash chute. When you emerge back in the gravity zone, kill the Slasher that emerges. The power has been deactivated and you'll need to grab a battery to start up the next passage. Take the now powered elevator to the tower residential area.
You'll have a brief encounter with Nicole before winding up at a Unitology church. There are however a large gang of Necromorphs waiting to bring the pain.
The key target is to kill the Infector so that it cannot form new enemies from any remaining human bodies. Kill off Exploders to deal damage to several enemies at once. The Leapers and Pukers are also somewhat of a threat so keep your distance. After clearing the area, proceed on to the church to end the chapter.