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.

Susan visits a psychiatrist to cope with the loss of Little Susie. Jeanie's estranged husband Al checks in the ER complaining of flu-like symptoms, which turn out to be caused by HIV. Shep expects Carol to back his version of events during an official investigation of his behavior. Loretta takes a turn for the worse. Doug discovers that his father has disappeared with a LOT of Karen's money.

Susan throws herself into her work to escape her stressful personal life, earning recognition from Kerry and Mark, who begins preliminary discussions on next year's chief resident. Carter needs a pedes rotation, and fast, with Doug to graduate med school. Doug takes up with his father's girlfriend. Shep overreacts and attacks an Asian boy interfering at a scene. Mark and Jenn try to discuss their divorce amicably, with unforeseen results. Benton is named Resident of the Year. Harper leaves for an OB rotation at Parkland in Dallas.

Carter engages in competition with new surgical resident-in-training Dale Edson upon learning that residents will be evaluated and graded; only the top ones advancing to second year. It doesn't help that Dale once had a relationship with Harper. Mark flirts with infomercial director Iris. Peter faces the fallout from his altercation with Doug when surgeons begin dropping him from procedures. Shep begins exhibiting uncontrolled hostility, first to a patient being abusive with Carol, then a pedestrian. Susan and Chloe try to reach an agreement regarding Little Susie.

Mark finds himself manning a very crowded ER on his scheduled night off, filling in while Doug is out with whiplash and Susan meets with her lawyer. He tries to juggle hunger pangs, 40+ patients in the waiting room and a never-ending stream of traumas.

Susan institutes extra precautions in case Chloe tries to reclaim Little Susie. Mark changes his look, growing a goatee and wearing contact lenses. Carol and Jeanie square off over the care of a transient. Carter celebrates when he receives his residency match, putting his patient and his job at risk. Shep, still suffering from Raul's death, is surly with new parter Reilly. Benton and Ross have differences when Peter discloses a critical mistake made by Doug, raising animosity between the two.

Shep and Raul respond to a massive fire without proper equipment, risking their lives to save addicts and their children. Shep will be okay, but Raul has third-degree burns covering his body; it's only a matter of time. The ER is flooded with burn victims. Chloe returns to Chicago. Doug is stood up by his father for a basketball game.

The ER hosts roughly a dozen pregnant women when a sprinkler bursts in the maternity ward. Carter plays tour guide for the visiting surgical intern hopefuls before going through the interview himself. Benton tries to bring a hopeless patient back from the brink of death in a marathon surgery. Jerry tries to convince the others that basketball player Scottie Pippen visisted. Doug visits his father.

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.

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.

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.

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.

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.

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.

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.

In the middle of a torrential rainstorm, Dr. Ross stumbles across a child trapped in a drainage pipe rapidly filling with water. Doug does everything possible to save the boy, Ben Larkin. Harper develops a bond with a young girl with separated parents.

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.

Dr. Ross treats the dying Chia-Chia. Susan tries to find a way to keep Little Susie, asking her parents for help. Benton treats an injured woman who refuses to press charges against her abusive policeman husband. Carol and Harper are tricked by a patient from the "turkey file." Lydia helps Loretta the prostitute outfit herself for a job interview. The staff celebrates Weaver's day off.

Weaver and Susan's feud escalates to the point where Mark needs to step in and fix it. Benton is involved in a parking lot altercation, resulting in a broken hand and Carter replacing him in surgery. Mark cares for an abandoned elderly woman. Susan tries to juggle her work and care for Little Susie. Shep risks his life to bring in a gunshot victim.

Carter gets his first patient...and loses him. Susan's feud with Kerry Weaver intensifies when Weaver demands all of Susan's procedures be cleared with her. Chloe abandons Little Susie again for a lucrative career in the flea market business. Carol finishes her paramedic recertification by picking up a very overweight, lethargic man. Shep hits on Carol. Jeanie ends her relationship with Benton. Wendy conducts interviews with various ER staffers for an article on Dr. Greene. Dr. Ross cares for a four-year-old Asian boy with AIDS.

Kerry Weaver manages to offend just about everyone in her first day as chief resident. Carol goes on a ride-along with paramedics Shep and Raul, sharing a ferris wheel ride with Shep. Peter and Jeanie's secret relationship comes to a head. Susan is stuck caring for Little Susie while Chloe attends school. Dr. Ross has his hands full with a young pyromaniac. Carter shows interest in med student Harper Tracy.

The ER treats victims of a gang shootout. Carter arrives late and unprepared for his new position. Mark learns all about being an attending, including senior staff's habit of bad-mouthing the residents, particularly Doug Ross. Mark hires a new chief resident, Kerry Weaver. New third year med students arrive to complete their ER rotation.