A business contractor with a bad heart gathers his family around him in the ER as he prepares for the end. Dr. Ross helps an asthmatic teenage girl when her mother doesn't have the funds. Carter worries that he may have contracted an STD from Liz. Dr. Lewis treats a teenager with alcohol poisoning. Jenn Greene prepares to move to Milwaukee.

The air conditioning quits on the hottest day in October which, coupled with closed ERs in Chicago's other two hospitals, leads to an extremely hectic day. Dr. Ross treats a six-year-old suffering from a cocaine overdose; Ivan Gregor, the liquor store owner, shoots and seriously wounds a young teenager. Susan's immature sister Chloe drops by, wreaking havoc in Susan's life. Doug picks up a pharmaceutical saleswoman, much to Carol's displeasure.

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.

Hathaway treats a rape victim. Walt brings Benton's mother to the ER with a sprained ankle. Carter shows his annoyance toward Benton and his stand-offish attitude. Mark calls in sick to spend time with his wife, leaving Doug as a hectic acting chief. Div shows signs of snapping, overreacting at the smallest provocation. The ER gets a new desk clerk, 'Bob'.

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.

A severe blizzard leaves the ER utterly devoid of patients, leaving the staff free to goof off. In the middle of their fun, a call comes from dispatch, informing the ER of a 40-car pile-up with dozens of casualties. The ER goes from being deserted to capacity. All surgeons are called in. Bob surprises everyone with a quick and life-saving decision. A new doctor, Angela Hicks, arrives just at the right time. Ross and Linda return from the Caribbean just as Carol makes a surprise announcement.

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.

Carter fumbles his way through his first look at surgery. Dr. Lewis' nemesis, Dr. Kayson, makes her New Year's Day decidedly unpleasant. Chloe announces she's moving to Texas with her boyfriend.

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.

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.

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.