The pilot for the popular TV series is set during 24 frantic hours in the lives of a group of doctors, nurses, and staff members of a busy emergency room at a Chicago hospital. They deal with the seemingly endless casualties that stumble into their place of employment. The central characters are the chief resident and family man Dr. Mark Greene, who is considering a job in private practice due to pressure from his demanding law student wife Jennifer; outgoing Dr. Doug Ross, who deals with cases in his own personal way; straight-arrow Dr. Susan Lewis, trying to get by another long 36-hour shift; inexperienced third-year med student John Carter; cocky surgical resident Dr. Peter Benton; and troubled chief nurse Carol Hathaway.

Carol Hathaway goes ahead with her plans to adopt Tatiana, but her past history makes her ineligible. Benton continues to trade shifts so he can spend time with his mother but it all catches up with him and he has a run-in with Dr. Hicks. Doug Ross treats an abused child. Green, Benton and Carter take extraordinary measures to save a man they later learned had signed a DNR. A consultant arrives to study procedures in the ER, but all is not quite what it seems. Mark Green's wife Jen has an important announcement. Benton's mother has a serious accident when he falls asleep on the couch.

Carter gets his first official patient while Doug treats a four-year-old Asian boy who has AIDS.

Benton dismisses a patient he hasn't seen who should have been admitted. Carter competes with Dale, a new surgical resident-in-training who once slept with Harper.

While on their helicopter flight rotation, Mark and Susan find an injured family of four who they bring to the ER.

Doug treats a dying 17-year old cystic fibrosis patient who doesn't want to be resuscitated. Carter gets to operate on Benton.

Jeanie believes she's been fired because she has HIV and fights her dismissal.

When a compatible bone marrow donor cannot be located, Scott Anspaugh agrees to undergo a new round of chemotherapy, even though there appears to be little point. Doug Ross suggests to Jeanie Boulet that Scott may have agreed to the therapy because of her. Mark Greene has taken on the task of organizing the annual ER banquet only to find that Jerry, on whom he had been relying for much of the preparation, hasn't quite delivered. John Carter confronts his grandmother when he learns that she has cut off funding for Carol Hathaway's free clinic. In the OR, Peter Benton has a major confrontation with Dr. Morgenstern, pushing him aside and taking over an operation. Greene and Weaver criticize Doug Ross over his handling of a sick child and her mother.

It's Christmas day in the ER. An 18-year-old boy arrives brain-dead, and Carter has to convince his parents to donate his organs, since a 16-year-old girl needs a liver. Benton risks his career by preventing Romano from operating under the influence. Ross and Hathaway have a religious dispute over how to deal with a pregnant 13-year-old. Corday is charmed by a musician who is facing surgery for prostate cancer. Dr. Lee flirts with Mark but turns out to have some major issues and strange story-telling habits.

Romano observes the ER, and rubs the staff the wrong way. Lucy finds out that an elderly patient's bedsore is really much more. Carter breaks up with his girlfriend. The power goes out at County General, and the doctors must keep critical patients alive. Corday investigates the rape of a comatose patient.

Carter and Lucy are discovered and the staff struggles to save them and go on with normal patient care.

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.

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.

Dr. Carter, Abby and other staff of the ER are quarantined as the CDC investigate a mysterious, deadly outbreak.

Harkins faces a tough call while treating a troubled teen involved in a car crash with her dad; Abby races to stop Maggie from taking manic-depressive Eric out of treatment; and Kovac hits a new low when an elderly woman tips him for his medical services. Meanwhile, an abandoned baby dredges up painful memories for Chen; and Pratt goes to bat for Leon after he's fired from his job for stealing.

Dr. Weaver bends the rules and treats the Alderman's lover for syphilis. Dr. Kovac's patient claims she was sexually abused at a boot camp for troubled youth. Dr. Carter treats a women with a nasty personality.

Carter greets the returning Kem, but their meeting with his father, Jack, gets tense after Carter announces plans for his grandmother's estate.

Kovacs stops to help a woman and her son whose car broke down. Steve is getting close to Alex, and Sam panics. Abby is looking for her letter whether to see she passed her boards. Pratt shows off his new Chrysler. Elgin tries to build a connection between him and Pratt. Jing-Mei might be battered by her senile father.

Weaver, Kovac, and the other doctors work frantically to try to save Jerry and a pregnant Abby, who were both critically injured during the shootout that left the ER in shambles. Meanwhile, Sam tries to escape from her ex-boyfriend and his criminal accomplices as they head north, but things quickly turn violent.

When a gunshot wound victim arrives, the new chief and Abby butt heads on how to treat the patient. Abby comes to Sam's defense when she goes before a nurses disciplinary board.

The Last One Before Christmas Break. The one in which Frank and Drs. Sanchez and Wade accidentally get brownies with cannabis in it. The one with the Christmas party. Archie's cousin brings Archie's deceased father's storage container to the ER bay. An injured pregnant Latino woman is brought in. There is something wrong with her baby?. Plus, the Immigration Office wants to deport her.

Neela experiences alternate versions of the same day.