Thomas Ian Nicholas

As Cristina tries to recover, she proves to be a very difficult patient, and a visit from her mother doesn't improve her demeanor any. And Meredith's mother, Dr. Ellis Grey, has the hospital staff running in circles. Jeremiah, a cystic fibrosis patient, could benefit from Dr. Addison Shepherd's medical knowledge, but her involvement in his surgery could delay her highly anticipated departure from Seattle Grace Hospital, leaving Meredith and Derek's relationship hanging in the balance.

Al gets a visit from a guardian angel and discovers what the Bundy household would look like if he was never born.

After receiving an electric shock while plugging in the Christmas tree, Al learns what life would be like if he had never been born.

Allison helps find a woman who jumped to her death, then learns that the boyfriend is Gregg Watt, a suicide hotline volunteer and son of defense attorney Larry Watt, who previously threatened to expose the medium.