Aaron, the staff, and the patients are caught in the crossfire when Antoine Metcalf, a gangbanger and career criminal, follows his latest victim into the E.R. to finish off the job he started, and sprays a room with automatic gunfire before hospital security shoots him down; Karen joins the staff, and successfully teams with Paula to remove hematomas that are preventing Marcus Lavelle from walking, but the trauma of witnessing his mother's being injured in the E.R. shooting leaves the little boy afflicted with hysterical paralysis and still unable to move although the surgery has left him physically fine; reluctantly operating on the shooter, Aaron jokes about how easy and perhaps appropriate it might be to cause Metcalf's death through a surgical hiccup, a remark which comes back to haunt him later when Metcalf dies soon after surgery and his family sues Aaron and the hospital for failure to provide adequate care; Arthur engages in a little ex parte communication to put in a good word

Jeffrey strongly objects when his old nemesis is hired into the plastic surgery department, but they are able to set aside their differences to bring some peace to the mother of a young girl who dies during surgery; a nurse impedes Aaron's plan to allow Karen to die peacefully.

When the gun belonging to a critically wounded police officer drops out of his holster in the E.R., the distraught brother of a man waiting for a donor heart picks up the weapon and threatens the staff unless his brother receives an immediate transplant; as Aaron and Danny operate on the wounded officer, one of the exploding bullets with which he was shot goes off and severs two of Danny's fingers; Geri performs a successful reattachment, but Danny may be facing the end of his career as a surgeon.