Returning from maternity leave, Carol (Julianna Margulies) has problems getting back with the program. Greene (Anthony Edwards) tries to nullify the abusive relationship between a gay couple. Carter (Noah Wyle) and Chen (Ming-Na) launch into another argument, this one over admitting an elderly woman (Peg Phillips) into the ER (Diane Baker guest-stars as the woman's apparently long-suffering daughter). Complications arise during a heart transplant for Lucy's (Kellie Martin) patient Valerie (Myndy Crist). Luka (Goran Visnjic) treats a group of truly colorful patients. Malucci (Erik Palladino) launches a one-man crusade against an illegal pharmacy. And two of the series' main characters may be on the verge of a warm relationship. ~ Hal Erickson, Rovi