Carol worries about a Russian girl with AIDS who's brought in and then abandoned by her foster mother. Kayson asks Susan to be his Valentine. Deb accidentally consumes LSD-laced chocolates.

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.

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.

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 Benton.

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

Carter finally works up enough nerve to ask Del Amico out. Jeanie tries to help Scotty decide whether to undergo an experimental treatment and Benton takes unexpected action during an operation with Morgenstern.

Benton's attempts to get away to Carla and Reese on Christmas Eve are continually thwarted by Romano, culminating in Benton forcing the drunken Romano away from a patient. Carter believes he's found a Christmas miracle when a teenage girl with a rare blood type needs an organ donation at the same time a brain-dead patient with the same blood type is in the hospital. After witnessing Dr. Lee rifling through Greene's locker, Jerry becomes convinced that she's stalking Mark.

The hospital suffers through a series of power outages. Carol's decision to send Doug a fax about her pregnancy is thwarted by the power outages. The staff is on alert after a raped and beaten patient is found in a hallway. Romano begs Corday to stay in trauma. Carter and Roxanne break up. Carter and Lucy treat a pheromone saleswoman.

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 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.

Abby is distressed when her mother interferes with Eric's treatment at a psychiatric hospital. Pratt treats a frightened young girl who has been injured in an auto accident and desperately wants to hide a secret. An unhappy Luka forms an unlikely bond with a lonely elderly woman who makes him a surprising offer. Chen is overcome with upsetting memories when a baby is abandoned in the emergency room. Pratt takes action after Leon is fired from his menial job.

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.

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.

Neela is upset when she finds out Abby's good news second hand; the new chief, Catherine Banfield, and Abby disagree on how to treat a gunshot wound victim; Abby defends Sam when she goes before a nurses disciplinary board.