Season synopsis
Contains spoilers for this season and earlier seasons.
Susan Lewis leaves County to join Chloe and little Susie in Phoenix. Before Susan boards the train, Mark Greene reaches Union Station, admits that he loves her, and asks her to stay; Susan kisses him and says she loves him too, but still departs. Mark's isolation deepens afterward. Near the season's end, he is attacked in a hospital bathroom in a random assault; he survives, but the beating leaves him frightened, angry, and increasingly distant from his family and coworkers.
Carter is now an intern, and his conflict with Benton over surgical intern Dennis Gant grows as Carter sees Gant being pushed hard and Benton refuses to soften his standards. Gant dies after being struck by a train. Police rule it an accident, but Carter fears Gant killed himself and blames himself and Benton for missing the crisis. Carla Reece gives birth to Benton’s son prematurely. The baby is in critical condition, leaving Benton anxious as he faces the responsibilities of fatherhood.
Jeanie Boulet's HIV status becomes known at County after Greene gains unauthorized access to her medical record. Weaver supports Jeanie as she confronts disclosure and stigma, and Jeanie later reunites with her former husband Al. Doug Ross and Carol grow closer through the season: Carol considers medical school but chooses nursing, while Doug questions his conduct after a former one-night stand dies. Their unresolved affection becomes explicit in a kiss near the close, as Mark's attack and recovery reshape the hospital around them.