In the lobby, Cuddy is still calling in when the SWAT team captain arrives. She tells him they heard a gunshot, and now no one's answering the phone. Lt. Bowman hangs up the phone and tells his men to "secure the perimeter." Cuddy doesn't like the sound of that. Lt. Bowman asks if a husband or loved one is one of the hostages, which is kind of a random question. "Uh ... no," Cuddy says, totally lying. Please. It's obvious to the SWAT team guy, and he's only known Cuddy for two seconds.
Meanwhile, a random PPTH hallway has been set up to treat the evacuated patients, and Taub, Kumar, Chase, and Cameron are treating away. Taub says House is going to get everyone killed. Kumar the Positive says that if Jason wants a diagnosis, then he's in there with the right doctor. Cameron reminds Kumar that House may be a brilliant diagnostician, but he also can't stop himself from pushing people's buttons, which isn't a good thing when the buttons you're pushing belong to a man with a gun. With that, they all get paged.
House answers his cell phone. Foreman, Cameron, Chase, Taub, and Kumar are all gathered around the meeting room phone. Hooray! This is excellent! The old Cottages are back! Oh, wait. Chase immediately decides that it isn't fair that a guy who threatens violence gets a bunch of doctors waiting on him hand and foot, and takes off. We won't see him anymore this episode. Why? Why can't they all work as a team? Just this once! I know it's completely in character for Chase to do this, but it still sucks. The differential, sans Chase, begins. Cancer, a neurological condition, lung infections, and a heart defect are suggested. House writes them all on Cuddy's wall-cum-Whiteboard. Nurse LookslikecarlafromScrubs announces that Migraine Man is going into shock, but no one cares. At least his migraine feels better. Meanwhile, the Kid criticizes House for having to write only four things down to remember them, like, what's up with his attitude? House tells Foreman to test Jason's blood and Cameron to look over his many medical files. Taub and Kumar will go to Jason's apartment, the address of which he gives readily. House says if Jason is giving them his address, then he must have no intention of going back there and thus, an "end game." Hope it's not the game of Murder Suicide!