Maura Tierney graduates from recurring actor to series regular in the role of OB nurse Abby Lockhart, who begins her first ER rotation during an outbreak of the flu. Elizabeth Corday (Alex Kingston) is less than enthused when her highly judgmental mother breezes into town. Benton (Eriq La Salle) and Romano (Paul McCrane) verbally duke it out over a tricky case. Carter (Noah Wyle) tries to aid a youngster afflicted with muscular dystrophy. And the evening yields two cases of illegal injections: One by the mother of a patient, the other by a patient himself.