It has been two months since the smallpox lockdown at County General. The Emergency Room is now swamped with patients due to the wholesale closings of many other ERs in Cook County. Likewise, there is huge influx of new med students, among them the outspoken Erin Harkins (Leslie Bibb), who is tired of waiting for her first orientation. Elsewhere, Corday (Alex Kingston) has returned to Chicago, only to be immediately unnerved by the bizarre behavior of Weaver (Laura Innes). Romano's (Paul McCrane) severed arm has been re-attached, but he's not out of danger yet. And Pratt (Mekhi Phifer) performs what amounts to a medical miracle.
by Hal Erickson synopsis