Tom Choi

Cristina's encounter with a former nurse, now a patient at Seattle Grace, changes her forever; Derek and Meredith treat a construction worker who has miraculously survived an injury but is now faced with tough decisions about his future; and a patient recognizes Izzie from a lingerie ad, which makes her the subject of hospital gossip.

Higgins' therapist hires her to look into why one of her teenage patients died of suicide.

The unit is called into action when a serial bomber terrorizes Seattle.

Jack's pain continues to get worse; the FBI copes with the latest deadly developments.

Michael comes face to face with the general and is betrayed by one of his own as the search for Scylla reaches its shocking end.

When Archer has a severe seizure, Addison and Naomi use every resource possible to determine the cause and a cure; Violet tells Pete and Sheldon that she is pregnant; Cooper cares for an abandoned patient.