Carol returns after her eight week absence, finding Doug holding himself responsible. Carter finds himself watching over a mysterious, mentally ill singing woman. Susan clashes with Dr. Kayson over a diagnosis. Dr. Greene treats a domestic violence victim.

Carter has a difficult day when he has to identify a dead teenager and notify his parents. It doesn't help that he notifies the wrong family. Doug woos Carol, despite Taglieri's presence in her life. Benton clashes with brother-in-law Walt after he neglects family duties.

Benton and Langworthy interview for the Starzl fellowship. A drunk Chloe throws a tantrum in the hospital. Benton saves a man with a throat wound, earning Morganstern's praise. Carter has a good day, winning a bottle of champagne and getting three leads on apartments. Carol has second thoughts about moving in with Tag after a spontaneous kiss with Doug.

Carter and Benton treat a suicidal transgender woman. Doug feels like a 'kept man' in his relationship with Linda Farrell. A patient entrusts Carol with the particulars in an accident. Cvetic continues to battle his demons, ending up wandering down the middle of a crowded street.

Benton makes a critical error when he publicizes the availability of a dying man's organs before obtaining the wife's permission. Lewis discovers that Cvetic has quit his job at the hospital, moved out of his apartment, and dropped out of sight. Carter makes a move on Susan. Chloe announces her pregnancy.

A case of apparent spousal abuse is not what it seems. Deb outshines Carter after he is up all night preparing for a presentation. Peter informs Jackie he's hired a helper for his mother. First Kayson's reprimand against Susan is denied, then Susan has a chance to prove herself when Kayson is brought in as a patient. Dr. Ross meets Diane Leeds, of risk management, and her son Jake.

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.

Peter refuses to sleep, despite Hicks' order, in the middle of a 48-hour shift. His lack of sleep catches up with him when he is supposed to be watching his mother. A doctor, who turns out to be a con artist, visits the ER to use it as a model for a new hospital, in the process offering Susan a job. Jenn tells Mark she wants to separate from him. Dr. Ross treats an abused young girl. Carol receives bad news about her attempt to adopt Tatiana. Morganstern informs Mark he's leaving for Boston and will be strongly recommending Mark to his replacement, leaving a surprised Mark uncertain as to his job prospects.

Mark, still upset over the loss of Jodi O'Brien, takes the night off but ends up in the ER anyway, albeit an hour late, when the new chief runs a drill at 2:00 a.m. Benton begins to realize his mother's future is not bright. Carter and Deb compete against each other. A small moon coinciding with the naturally heavy Saturday night traffic causes an exciting night.

Susan has her hands full with a pregnant Chloe. Benton goes to dinner with Jeanie. Greene further alienates Swift when he decides to honor a family commitment rather than stay longer at the ER to help him. Carter makes a good impression on Dr. Swift. Doug turns down an offer to "celebrate" with Linda Farrell, instead getting more serious with Diane as he agrees to coach Jake's Little League team.

Susan is forced into the role of parent when Chloe gives birth and both Chloe and her mother, Cookie, shirk responsibility. Doug is surprised and a bit frightened when Diane suggests they move in together. Unfortunately, Linda Farrell happens to be around to take advantage of his nervousness. Carter is offered the ER sub-I but turns it down in anticipation of receiving a surgical position. Peter receives unpleasant news; his mother has died.