Abby, Carter, Chen, Pratt, and Stan will be confined to the ER for two weeks, while all of the other patients are evacuated and sent to different hospitals. While on the roof arguing with Luka about the use of a helicopter, Romano backs up into the tail rotor, and has his arm severed above the elbow. Anspaugh arrives to perform surgery, and reattaches the arm. Susan is stuck on the roof with a dying patient. After 2 weeks, the ER reopens. While all of this has been going on, Elizabeth has been in London, working at her father's hospital, where her supervisor doesn't like the American mannerisms and vocabulary she's picked up. She ultimately decides to return to Chicago.

Lewis treats an end-stage Huntington's patient, whose mother has already watched her husband wither from the disease. Abby's brother Eric, an Air Force traffic controller, visits on his way to a new post in Nebraska. Carter tends to a 12-year-old drug-addicted prostitute with a serious STD, until her pimp shows up and whisks her away. Pratt aggravates a drug-seeking man who comes back brandishing a gun at Chen and Abby and demanding Demerol. Abby gives him his shot but purposefully ODs him. In the aftermath, Carter flips his lid, demanding better security and the installation of metal detectors. When Weaver refuses, Carter leads a walkout. Weaver eventually caves, albeit before telling Carter that he must fire three senior nurses by the next morning to make up the expense. Abby, Lewis and Chen go to a concert to decompress.