The realities of the ER may be too much for a child, but circumstances force Greene to bring his daughter Rachel with him on a day when the outdoor temperature tops 100 degrees and the air-conditioning doesn't work. Benton and Langworthy try in vain to save a boy shot in self-defense. Meanwhile, Lewis's broke sister, Chloe, steals Lewis's TV and VCR. After Ross crosses the line with Hathaway and Taglieri, Hathaway slugs Ross.

Doug Ross' hopes of renewing his relationship with Carol Hathaway take a positive turn after the two of them kiss following a particularly stressful trauma, but his hopes are dashed when she decides to move in with boyfriend Tag. John Carter has a particularly good day when Dr. Green successfully walks him through a complex procedure. Haleh takes Dr. Benton to task when he refuses to act as a role model for a young gangbanger she has an interest in. Benton is also competing with Dr. Langworthy for a prestigious fellowship. It's Susan Lewis' birthday and her sister Chloe shows up at the ER drunk.

Carol Hathaway faces an ethical dilemma when a patient admits that he, and not his friend, was driving the car that ran a red light and killed a pedestrian. She decides to tell Tag about kissing Doug Ross. It's Thanksgiving and the doctors treat an animal rights activist who was attacked by the turkey he was trying to save. Doug Ross is going to the Bahamas with Linda Farrell and he is very much feeling like a kept man. Carter has to treat a transgender woman who has now reached an age where she can no longer pass as a woman. Carter's indifference is the final straw. Susan Lewis continues to worry about Div Cvetic, whose condition seems to be worsening.

The ER staff's slow snow day becomes chaotically hectic when the casualties of a 40 car traffic accident flood in.

It's Christmas-time and the expected range of emotions is to be found among the ER staffers. Susan Lewis treats a middle-aged woman who is overjoyed at finally getting pregnant. Susan is also shocked to hear that her boyfriend Div Cvetic has quit his job and moved out of his apartment. Mark Greene treats a young drowning victim. Doug Ross takes Greene's advice and decides to tell Carol Hathaway that he loves her; unfortunately he chooses to do so at her engagement party. Peter Benton jumps the gun and arranges for transplant teams to harvest an accident victims organs but the man's wife is now refusing to give consent. Susan's sister Chloe announces that she is pregnant.

Susan Lewis has a run-in with Dr. Jack Kayson, the cardiology attending, when he accuses her of not providing him with all necessary information on a patient who subsequently died. He makes it very clear that Susan will bear all responsibility for his death. Her sister Chloe informs her that she and her boyfriend are moving to Texas. John Carter is still frustrated by Peter Benton's apparent lack of interest in teaching him anything but a new go for it attitude leads to an invitation to assist in a surgical procedure. Benton's sister suggests to him that the time has come for them to put their mother in a care home.

Greene finds his marriage falling apart and is concerned at how little time he's spending with his daughter. He also treats an eight week old child with a heart murmur who requires surgery. Susan tries to get her pregnant sister Chloe to take her pregnancy seriously, but her head isn't quite into it. Benton tries desperately to find a surgeon who will operate on a 16 year-old with a severe brain aneurysm that could burst at any time. He's also concerned at his mother's care and is growing ever more attracted to Jeanie Boulet. Doug Ross' commitment to Diane Leeds gets more serious when he agrees to be an assistant coach for her son's little league baseball team.

On a fateful Mother's Day, several staffers in the ER face possible life-changing events. Susan Lewis' sister Chloe gives birth to a beautiful - and healthy - baby girl. Things start to go wrong however when their mother Cookie - who had agreed to take in Chloe and the baby - suddenly decides she's done enough and Susan will have to take care of it. Carter turns down an offer for an ER sub-internship in the hopes that he'll get an offer in surgery. Dr. Hicks has news for him however. Benton's mother takes a turn for the worse. Carol Hathaway is overwhelmed with the final preparations as her wedding day approaches.

The feud between Susan and Weaver gets to the point where Mark has to step in.

Doug saves a kid who's stuck in a flooded culvert and becomes a local hero when a TV helicopter films part of the rescue operation.