Oxygen will return in a few seconds after 'Chapter 4' dissipates from the screen.
I recommend you don't follow the locator for a second so you can head to the Store and the Bench in the Gift Shop just the other way from the Locator line.
Save station here, too.
A power node is also in the Reading Wing near the gift shop as well.
So is Flowerface.
After you find the Power Node, Stross will spam facetime with you again.
Keep following the Locator till you happen upon this room, filled with Pukers, Slashers, and oh-so-fun Infectors. Don't get overwhelmed, aim for the Infectors.
Once they're all dead, head to the cargo lift just past this door.
After some troublesome pukers you'll happen upon another glass-window room that has a tiny little puzzle to it.
See this flap? Kinesis it off.
Then kinesis another flap behind you till you find a little box which you can then Kinesis into this port to progress.
Slashers will then ambush you, feel free to shoot out the glass (but don't forget the triangle!)
The door will malfunction, slamming like crazy, so try to Stasis it till you can pass by without dying.
After Flashlight makes an appearance (Is her name like, Nicole or something?) you'll happen upon another save station.
Head into the crawlspace, but prepare for a button sequence with Flashlight, where you'll stand eye to eye....
Ha ha, I make great puns. Press E before your eye exam takes a turn for the worse.
Isaac will then realize he's about to seppuku.
A power node will be on the table right after Isaac stops going crazy.
Proceed to this large room, you'll be hounded by these little chargers called Stalkers once you get downstairs via cargo lift. Stop them with a Javelin Gun, or if you're too cheap then use the spears on the ground.
After you make a dialogue with Daina about the door splitting in twain, the Stalkers will show. You cannot stop their charge, only via stasis or their death. IF they hit you they'll take off a large amount of HP and retreat.
Luckily, they come one at a time.
Once the Stalkers are dead you can proceed to the Funeral-ery-ry wing (whatever the game called it) where you'll be attacked by some Slashers and Swarmers. Man, this game loves the letter S.
Proceed to the elevator and mention to this fine fellow that he is a terrible actor with a spear to the face. I mean he's feigning death and will slash you.