Weaver returns to the emergency room after a self-imposed sabbatical of three weeks, wondering how her newfound lesbian identity will affect her workplace relationships. Having purposely allowed a mass murderer to die, Greene must keep the secret amidst the scrutiny of his superiors.
Carter is overwhelmed by patients from a rock concert riot. Benton's former girlfriend and Reece's mother is killed in a car accident. Newly promoted to chief resident, Chen panics and misdiagnoses a patient. Kovac angers Abby by flirting with a waitress.
Greene's daughter comes to live with him and Corday. Carter and Abby become more intimate. Chen must prove her skills while saving a baby. Weaver terminates Malucci after witnessing him having sex in an ambulance.
Dr. Susan Lewis arrives, looking for work in the Chicago area again. Greene hires her, over Weaver's objection. Chen nervously attends a risk management review, accompanied by the unforgiving Weaver, to discuss a patient who recently died under Chen's supervision.
Lewis faces a hectic first day back at County General. Benton and Roger become frantic when they can't locate Reese. Carter's grandmother is brought to the emergency room. Carter and Abby deal with inept medical students.
Corday's ordeal, caused by the recent infection-related deaths of several of her patients, worsens when she is closely observed by a stern taskmaster. Corday is outraged when a county investigator accuses her of deliberately euthanizing the patients, who all happened to be elderly.
A new medical student, Michael Gallant, arrives in the ER. He's supposed to be working under Dr. Carter's supervision but John's grandmother is unwell. Elizabeth Corday is convinced that other doctors are refusing to work with her as a result of the mysterious deaths. Mark Green thinks she's overreacting but she's determined to find out what happened to her patients. Abby and Luka argue over the attention he is paying to a trainee nurse's aide. Dr. Benton finds himself in court to retain custody of his son, Reese. Carter and Susan Lewis treat a young woman who is both...
When a torrential rainstorm pounds Chicago, patients deluge the emergency room while Weaver speeds to an accident site. There, she finds a pregnant woman, Vicki, lying injured inside a wrecked ambulance while live power lines spark. Fourth-year student Michael Gallant makes a dangerous decision in order to help.
Peter Benton continues his court fight against Reese's stepfather, Roger, who seems to have the upper hand. When a woman is accidentally shot during a gas station robbery, Dr. Corday tries to convince the husband to let them harvest her organs. A 15 year old boxer is brought in with a head trauma after sparring with his older brother. Newlyweds are having trouble when she constantly breaks out in a rash; Carter thinks he knows the cause. Luka tells Abby that he may marry Nicole, who has told him she is pregnant. Dr. Green lays down the law when the police bring in a ...
Dr. Greene's final days are spent in Hawaii with Rachel, teaching her to drive and surf. When he suffers a seizure, Elizabeth is called. Mark refuses to go home. He manages to make amends with his daughter before his eventual death.
Just when the ER is understaffed and swamped, two children who were brought in turn out to have full blown smallpox. The entire ER must be locked down. The staff needs to improvise while they battle not only the disease but also frayed tempers.