Run forward through the decrepit hallways and twist around to find a Necromorph grabbing a corpse and pulling it into an air duct. Run left and head down the hallway through the door. Run up ahead and head into the space to your left for some ammo and other goodies. Once you've picked up your spoils, a rather amusing illusion takes place followed by a quick flash of darkness. Everything's back to normal...or is it?
Turn left and exist the room. Take your first right here and head inside to see the beginnings of a massacre, but be ready for a Necromorph to jump out in front of you. You know what to do, or do you? After some questionable visions activate the console in front of you, then turn and exist the room, being careful to exterminate the enemies who pop up. You're now back in the rust-colored corridor from before, and another baddie awaits you. Take it out, then head through the door it was blocking. Head into the larger area and into the left corner. The Ripper will be here in one of the lockers. Head through the door by the yellow Peng advertisement...or not. Another lockdown. Time to put your new Ripper to good use. Eliminate all enemies here, then head back through the door by the Peng sign.
Activate the console in here, and leave through the door by the "Safety Begins with Teamwork" sign. As you move ahead another baddie will pop up to say hello, so feel free to bash its skull in. Head through the door at the far end of the room and into another area which asks you to hack the security panels. Run around to the right past the first wall to activate a console. Head to the opposite end to switch on another. Exit the room through a door in the middle of the converging paths. Activate the console by the "Safety" sign and go out the door to the left. Everything is bathed in red now, of course, as you watch necromorphs wreaking havoc on the enclosure to your left.
Run around the perimeter of the room to remove threats until the quarantine has been lifted, and exit the room to head out into a winding corridor with lockers and wreckage at the end. Turn left and run ahead through a bloody mess, taking out the enemy on the way. Head through a room with corpses hanging from the ceiling and through the adjoining room. Exit into a blood-soaked corridor, heading straight until you can make your first right. A bizarre torso-monster makes its way down the hall. Follow it and take it out. Head back to the bloody hall and straight through the door up ahead. Activate the Bench here for upgrades and then run right over to the tram.
During the tram ride you'll need to protect yourself for the entirety of the ride, so get rid of all threats. Once the tram ride comes to an end you've reached the end of Chapter 3.