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.

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.

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 a law and a medical student. Green has to collect his daughter at school when she is suspended.

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 high school student and he learns that his daughter is outside sitting in the police car.

Dr. Benton is awarded full custody and Roger receives visitation every other weekend.