Abby (Maura Tierney) has just about reached the end of her rope: Her biploar brother, Eric, has vanished, and her bipolar mother Maggie (Sally Field) has come back into her life. As Carter (Noah Wyle) tries to help Abby cope with her many burdens, a shaken and humbled Kovac (Goran Visnjic) returns to the ER -- albeit only after receiving an ultimatum from Weaver (Laura Innes).