Haley Ramm

The doctors of Seattle Grace help Izzie cope with the loss of her fiancé, Denny, and her decision to quit the internship program. Meredith must decide what the future holds after her hospital liaison with Derek. The Chief is confronted by his wife, Adele, after spending the night in his office, and George seeks relationship advice from a surprising source, on the season premiere of "Grey's Anatomy."

Dr. Shaun Murphy's unique ability to relate to a patient isolated by an immune deficiency yields an unexpected result. Meanwhile, Dr. Claire Browne, Dr. Morgan Reznick and Dr. Marcus Andrews treat a 12-year-old patient who is about to become blind, and tension builds between Dr. Neil Melendez and Dr. Audrey Lim.

The Lightman Group investigates the disappearance of a young woman, which leads them to uncover a criminal element in the adult film business.

A roller coaster runs off its track, leaving six people dead. The CSI team investigates whether this was an accident or foul play.

Unable to communicate with the outside world, the Unit and their families must survive when a deadly gas poisons anyone in their community who steps outside.