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.

Benton commits perjury on the witness stand in order to gain custody of Reese. When Romano refuses to give him a more even schedule, Peter resigns and seeks a job at the clinic where Cleo is newly employed. Benton is granted custody of Reese and he and Cleo decide to move to the suburbs together. Meanwhile, Carter's father visits for Christmas with the news that he's getting divorced, Weaver and Sandy Lopez finally go on a date, and Abby catches Nicole in the maternity ward, recovering from an abortion.

After Dr. Corday moves out, Dr. Green fights loneliness and pain by immersing himself into his work. He is treating a father in the ER who severely burned himself while experimenting with illegal drugs. Abby fumes when the man who beat her is released and moves back in next door; the returning Jerry clashes with fellow desk jockey Frank.

Drs. Corday and Greene are awkward when working together in the ER. Dr. Weaver treats victims of an intense fire that may take the life of a dear friend.

On a busy Halloween night, Carter and Abby are the only staffers in costume when victims of an apartment building fire pack the ER. Corday takes on a new med student for a surgical rotation - Paul Nathan, who suffers from Parkinson's disease and decided to pursue medicine after being diagnosed. Despite a difficult first day, both professionally and medically, Nathan makes a difficult diagnosis. Romano's rehab lags behind his expectations, and he begins to doubt his role in surgery is no longer an option.

Dr. Romano seizes control of the ER and manages to offend everyone. Dr. Kovac asks Dr. Corday's help in the quest to bring a sickly Croatian boy to the U.S. for medical treatment.