Speculation runs through the ER, on a very hectic day, about Randi's possible criminal history. Mark faces an ethical dilemma when he has to decide whether to report yet another of Doug Ross's indiscretions--Doug slept with med student Harper Tracy. Carter becomes upset when Harper confesses this to him. Carol meets with a mobile notary to finish the paperwork to purchase a house. Bernstein informs Doug that he need to look for other employment. Benton is visibly upset when Jeanie begins work in the ER as a physician's assistant.

Doug's heroics earn him a second chance as Bernstein and Morganstern ask him to stay on. Doug and Mark clash when each treats a seriously injured patient and want to use the same equipment. Benton learns that Jeanie has separated from Al. After missing an earlier diagnosis, Carter overcompensates on his next patient and catches a break when the test results reveal something. Shep gets on Carol's bad side when he makes disparaging remarks about the people who make botched suicide attempts. Doug gets a phone call from his estranged father.

Carol and Jeanie try to find a home for a schizophrenic architect. Carter signs Benton up for an interview with Vucelich for a prestigious study. Carter and Harper try to find a place to make out. Jenn and Rachel are involved in a car accident; Mark is thrown for a loop when he learns that Jenn has been having an affair with a coworker. Doug dines with his mother. Susan receives $3000 in the mail from Chloe.

The ER staffers are in decidedly unfestive moods as Christmas arrives. Carol's spirits are lifted by a Santa-like patient. Mark is outraged when Jenn decides to stay in Milwaukee over Christmas. Benton and Carter score points with Vucelich when Carter convinces an older gentleman, Ruby, to include his wife in Vucelich's study. Mark gives a deposition in the O'Brien case. The death of a priest threatens to start a gang war. Weaver receives a surprise visit from an African friend. A Holocaust survivor, the victim of a carjacking, brings Chanukah to the ER.

Shep and Raul bring a dozen malnourished and abandoned children into the ER, keeping everyone very busy. Shep has a run-in with Malik and Benton when he makes an off-handed racially insensitive remark. Carter's high from the admission of Mrs. Rubadoux to the study ends when she shows no signs of recovery. Jeanie and Carol clash when Jeanie receives a poor evaluation. Al asks Jeanie to give him another chance. Mark is served with divorce papers.

Mark tries to find a way to tell Rachel about his impending divorce. Benton attends a banquet at Vucelich's home, with Jeanie as his date. Carter finally tells Mr. Rubadoux about his wife's terminal condition, making the man furious. Morganstern is admitted to the hospital after breaking a leg at a Scottish family reunion.

Mark is riddled with self doubt as the hospital prepares to settle the O'Brien suit. Kerry appoints herself as Susan's personal mentor. Carol mind a bucketful of expensive worms. Doug balks at counseling a teenage boy who thinks he might be gay. Benton uncovers some disturbing information concerning Vucelich's study. Carter steals a diagnosis from Harper.

Benton decides to blow the whistle on Vucelich's unethical study methods, causing Vucelich to drop him from the study. Susan treats a street couple, one of whom has passed HIV to the other. Doug receives a visit from his estranged father. Carter spreads rumors about an affair between Mark and Susan. Mark buys a motorcycle. Prostitute Loretta has cervical cancer.

Carol is pushed to the breaking point after another day when politics triumph over health care, and she quits. Dr. Greene "trades his soul" when he agrees to back Weaver for ER attending, in exchange for her support of Susan for chief resident. Jeanie takes an HIV test and informs Peter he should get himself tested as well. Carter invites Benton to his med school graduation, which he himself misses. Shep's refusal to see a psychiatrist risks his relationship with Carol.