A day's worth of trauma takes its toll on the men and women of the ER. Dr. Greene looks into leaving the ER and joining private practice. Among other events, multiple casualties are brought in when a building collapses. New medical students report for duty, including Dr. Benton's new trainee, the young and inexperienced John Carter.

Dr. Lewis tries to get a mentally disturbed individual admitted to the psych ward. Carter has a difficult day, treating many members of wedding party, suffering from food poisoning. Dr. Ross finally visits Carol, eight weeks after her suicide attempt. Dr. Greene deals with an elderly gentleman having a difficult time letting go of his dying wife. He also discovers that Jenn passed the bar exam.

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.

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'.

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.

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.

Morganstern invites Mark to join the staff as an attending physician. Mark treats an woman with breast cancer, who begs him to kill her. Deb "wows" Benton with her amazing presentation, leaving Carter in the rear again. Benton offends Haleh, who spends her day making his job extremely more difficult. The ER gets new crash carts, which are promptly stolen by cardiology.

Dr. Hicks berates Benton when he tries to switch shifts to attend his mother's birthday party. A teenage girl, a frequent patient of the ER, is brought in for a drug overdose. Carol decides she wants to adopt Tatiana while Tag isn't so sure. Dr. Ross slugs an abusive father in the lobby. Jen accepts a job offer in Milwaukee despite Mark's offer from Morganstern. Deb and Carter await the arrival of sub-internship applications.

A busy Dr. Greene goes all day in solving his patients' problems until he encounters the case of a pregnant woman suffering from complications that threaten both her life and her unborn baby's.

Deb and Carter compete furiously for procedures after Benton announces their books are due a week earlier than previously announced. Deb commits a nearly deadly error on a patient while trying to keep up with Carter. Doug's relationship with Diane Leeds grows. Peter and Jackie decide to put their mother in a home. Dr. Greene is put on trial, so to speak, in the M conference for Jodi O'Brien. Chloe returns.

Mark and Jennifer struggle to remain together as Mark has moved in with her in Milwaukee. Doug coaches Jake's little league team. Chloe's irresponsibility wears Susan down. Carter asks Benton to fill out a recommendation for the ER sub-I. Carol and Tag try to write their wedding vows; he becomes upset when Carol invites Diane Leeds, knowing that she'll bring Doug. Peter exhibits a growing attraction for Jeanie. Susan discovers what happened to Div when she spies his picture in a cabbie's dating service photo book. The staff discovers that Carter comes from a wealthy background.

Carter faces his last day in the hospital with aplomb, harshly grading Benton on an evaluation report. He later rescinds the report after finding out that the surgical sub-I is his. Carol faces wedding day jitters, culminating in Tag's deciding to call off the wedding. Chloe disappears again, abandoning little Susie with Susan. Dr. Swift changes his mind and decides to support Mark. Jake visits Doug.

The ER treats victims of a gang shootout. Carter arrives late and unprepared for his new position. Mark learns all about being an attending, including senior staff's habit of bad-mouthing the residents, particularly Doug Ross. Mark hires a new chief resident, Kerry Weaver. New third year med students arrive to complete their ER rotation.

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.

Speculation runs through the ER, on a very hectic day, about Randi's possible criminal history. Mark faces an ethical dilemma when he has to decide whether to report yet another of Doug Ross's indiscretions--Doug slept with med student Harper Tracy. Carter becomes upset when Harper confesses this to him. Carol meets with a mobile notary to finish the paperwork to purchase a house. Bernstein informs Doug that he need to look for other employment. Benton is visibly upset when Jeanie begins work in the ER as a physician's assistant.

Doug's heroics earn him a second chance as Bernstein and Morganstern ask him to stay on. Doug and Mark clash when each treats a seriously injured patient and want to use the same equipment. Benton learns that Jeanie has separated from Al. After missing an earlier diagnosis, Carter overcompensates on his next patient and catches a break when the test results reveal something. Shep gets on Carol's bad side when he makes disparaging remarks about the people who make botched suicide attempts. Doug gets a phone call from his estranged father.

Mark is riddled with self doubt as the hospital prepares to settle the O'Brien suit. Kerry appoints herself as Susan's personal mentor. Carol mind a bucketful of expensive worms. Doug balks at counseling a teenage boy who thinks he might be gay. Benton uncovers some disturbing information concerning Vucelich's study. Carter steals a diagnosis from Harper.

Shep and Raul respond to a massive fire without proper equipment, risking their lives to save addicts and their children. Shep will be okay, but Raul has third-degree burns covering his body; it's only a matter of time. The ER is flooded with burn victims. Chloe returns to Chicago. Doug is stood up by his father for a basketball game.

Mark finds himself manning a very crowded ER on his scheduled night off, filling in while Doug is out with whiplash and Susan meets with her lawyer. He tries to juggle hunger pangs, 40+ patients in the waiting room and a never-ending stream of traumas.

Susan visits a psychiatrist to cope with the loss of Little Susie. Jeanie's estranged husband Al checks in the ER complaining of flu-like symptoms, which turn out to be caused by HIV. Shep expects Carol to back his version of events during an official investigation of his behavior. Loretta takes a turn for the worse. Doug discovers that his father has disappeared with a LOT of Karen's money.

It's the first day of Carter's internship. He has a 36 hour shift and overnight he has to cover the ER, the ICU as well as the surgical patients.

Doug's one-night-stand has a seizure and he brings her to the ER.

Encouraged by Carol, Mark finally asks Susan out. Benton tries to save a boy, despite the fact Doug thinks he's brain dead.

Mark and Kerry have to create a policy regarding HIV-positive employees, which leads to gossip amongst the nurses.

Carter feels guilty about Gant's death. Benton doesn't want to talk about it.

Nurse Carol Hathaway is held hostage during a convenience store robbery, then befriends one of the gunmen.

Benton tries to find out if everything's OK with Carla's baby. Carter tries to get a man operated, despite the fact Anspaugh thinks he will die no matter what.

Carter is exited about getting his own med student and Mark and Carol interview candidates for the desk clerk position.

Carol would like to have a women's and children's health care clinic within the ER. Benton has trouble combining work and fatherhood.

Benton has a very extraordinary and interesting case when he comes across a boy with reversed internal organs.

Dr. Anspaugh's 13-year-old son is brought in and Anspaugh asks Mark to look after him. Another old lady who has been raped is brought in.

Greene flies to San Diego when his mother falls and is hospitalized. His concern increases when he finds her acting "completely loony and out of control." To make matters worse, he butts heads with his dad over her care.