The work never ends for the physicians and staff in the emergency room of Chicago, Illinois' County General Hospital. Naove Dr. John Carter (series star NOAH WYLE) has just graduated from medical school and is now a doctor, working as a surgical intern. He feels confident because the other interns training with him have never worked at County and are unfamiliar with their new supervisor, intense surgical resident Dr. Peter Benton (series star ERIQ LA SALLE). Benton makes Carter train as hard as the others. After botching an operation, Carter offends the nurses, and they make his busy night hellish. Fortunately, one intern, Dennis Gant (recurring guest star OMAR EPPS), helps Carter when he needs it most, and Carter's performance improves. But his rivalry with another new intern, Dale Edson (recurring guest star MATTHEW GLAVE), with whom he has clashed before, is renewed.

Handsome pediatric emergency fellow Dr. Douglas Ross (series star GEORGE CLOONEY) fails to convince recently divorced family man Dr. Mark Greene (series star ANTHONY EDWARDS), an attending resident, of the joys of casual sex with women. Ross' coworkers are all unimpressed by his behavior when he ends a relationship with a needy woman by calling her answering machine.

Physician assistant Jeanie Boulet (series star GLORIA REUBEN) discovers that she contracted the HIV virus from her husband. Benton, who had an affair with Jeanie, tests negative for the disease. Although he is sympathetic to Jeanie, he questions her decision not to tell the hospital about her diagnosis.

Meanwhile, everyone is worried that the hospital will be closed permanently, especially capable head emergency room nurse Carol Hathaway (series star JULIANNA MARGULIES). Hathaway almost quit recently in protest over the bureaucratic health care system. Also, Greene clashes with abrasive Dr. Kerry Weaver (series star LAURA INNES), who is his equal since her promotion to attending physician. Weaver confuses and angers everyone, including tough, talented emergency resident Dr. Susan Lewis (series star SHERRY STRINGFIELD). And the paramedics beat the emergency room team in softball at the Fourth of July picnic. Hathaway sees "Shep" Shepherd (recurring guest star RON ELDARD), her former lover, there with his new girlfriend.