Doors that protect them from Grievers didn't close? Check.
In typical paranoid-leader fashion, Alby has Teresa thrown in the Slammer because he knows she has something to do with everything, though he has no idea what.
Thomas tries to reassure her by speaking telepathically, but she doesn't respond so it probably didn't work.
Back in the middle of the Glade things have erupted into chaos.
All the boys are going to sleep in the Homestead, which is being barricaded against the inevitable Griever attack.
Frypan is making boys bring all of the nonperishable food into the Homestead in case they get trapped there.
Minho has ordered the weapon room's stock to be brought there as well, but he is on some secret special assignment from Newt.
Thomas begs Newt to release Teresa, and he agrees to let her out tomorrow when they've had a chance to figure some things out. He also convinces him that a few boys need to stay out in the Maze overnight for analysis, especially since staying in the Glade no longer offers protection.
Thomas goes to the Slammer to say goodnight to Teresa and to let her know he's got her back before going into the Homestead for the night.