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.

Billy Kronk, a hotshot young surgeon and recreational hockey player, arrives in the E.R. with a critically ill teammate and immediately takes charge, steamrollering over Phillip; Alan deflects a suit by Nabbott, but not before bristling at Harold's ""toad"" routine in court and being thrown into jail for contempt; Billy convinces a psychotic mugger with a history of pica who has bitten off the finger of a concert flautist during a robbery to submit to an endoscopy to retrieve the digit; as Geri successfully completes the reattachment, Billy and Phillip discover a second finger in the thief's digestive tract, and realize that the musician has been given a digit belonging to yet another of the mugger's victims.

Laurie asks Jeffrey for a divorce so that she can marry Gilbert Weeks, a lawyer who is also a patient at the Institute; spurred by this news, Jeffrey suggests that Aaron perform an experimental procedure which may cure Laurie's schizophrenia; fearful that Laurie will no longer love him if she is cured, Gilbert goes to court to stop the procedure, citing Jeffrey's conflict of interest and contesting his guardianship of Laurie; although she is torn between the two men that she loves, Laurie decides that her future is with Gilbert and declines the surgery; Billy becomes a member of the staff, and agrees to do a consultation on Tamara, a teenaged patient of an old friend, Dr. Dennis Hancock; after Tamara is diagnosed with breast cancer and refuses to have a mastectomy and reconstructive surgery despite warnings from Billy and Geri that she will die without the surgery, Dennis uses just the right approach to change her mind and allay her fears of disfigurement.

Dr. Kronk's feelings towards his girlfriend undergo changes when he find out about her past. Geiger's heart patient develops an aneurysm which would take him off the heart recipient list unless highly experimental methods are tried. Meanwhile, Dr. Hancock's ejection from his clinic leads to bringing the HMO provider into the courtroom.

When the Board of Health closes the hospital doors after several patients die from a deadly staph infection, the staff scrambles to find the source of the infection; Jeffrey and Geri help each other work through feelings of grief, loss, and guilt.

Billy arrives home just in time to save his dog Gordie from the fire that's engulfed his apartment, and ends up rooming with a reluctant Danny until he can find a new place to live; when a teething Alicia keeps her father up at nights, an exhausted Alan is thrilled when Diane offers to help out; when a racist teenager on the transplant list refuses the heart of a murdered black teenager, the hospital offers it to another candidate, but the boy's mother sues to have the heart transplanted into her son; Alan decides to get back into the social swing by asking Diane out on a date; Kate's inattention to pre-op labs results in the post-op death of the transplant patient; Danny overcomes his dislike of Gordie long enough to notice that he's critically ill, and by acting quickly, saves the dog's life.

Kate is stricken when she realizes that her negligence due to exhaustion caused the death of a young woman during surgery, and considers assuaging her guilt by informing the woman's parents of her error; Billy and Danny decide to help a teenager running a unlicensed clinic for indigent patients; Judge Aldrich retires from the bench and comes to work at the hospital as Alan's replacement; Camille's drug seeking behaviors continue; Diane has second thoughts about her research project when she realizes that she's become attached to the orangutan that she's successfully infected with AIDS.

Judge Aldrich's tenure as Alan's replacement is cut short by illness; Amy, an old friend of Danny's from medical school, joins the nursing staff and clashes with Camille over the care of a terminally ill patient; Kate and Billy hook up, but decide that they won't repeat the experience after they clash professionally during experimental laser surgery on an elderly cardiac patient; Amy rebuffs Danny's advances.

Aaron consults Dr. Gina Simon, a pediatric neurosurgeon after being presented with a 9-week old baby suffering from seizures. Jeffrey Geiger returns to the hospital and promptly fires half the staff, whom then sue to get their jobs back.