When a series of deaths occur at Seattle Grace, the uncanny events bring out the doctors' superstitious sides. Four deaths in the morning implies that three more deaths are due for the day. This makes Izzie nervous about Denny's surgery, and a jealous Alex informs Denny of the likelihood of his death, prompting Izzie to completely end their relationship. Meredith and Bailey treat a woman who claims to have been struck by lightning, but the patient keeps lying about the true cause of the injury. Cristina treats a patient in a car accident who has OCD. Meanwhile, Derek and Addison discuss making a more permanent living arrangement, and Dr. Webber treats a former sponsor from his Alcoholics Anonymous group. George is tasked with stealing back one of Burke's caps from Cristina. Izzie kisses Denny after he survives his surgery.