On her first day at Pittsburgh's Angels of Mercy Medical Center, L.A.-transplant Lydia Fiore, the new ER attending physician, loses a patient: the Chief of Surgery's son. Now, to save her career, Lydia must discover the truth behind her patient's death, even as it leads her into unfamiliar-and risky-territory. At least she's not alone. There's med student Amanda, a sweet Southern belle with problems of her own; Gina, a resident with a chip on her shoulder; and Nora, the no-nonsense charge nurse with a cool head but a fiery temper. Not to mention the paramedic who'd like to try out his bedside manner on Lydia.