S1, E23: J.D. (Zach Braff) begins to think Dr. Cox (John C. McGinley) may have feet of clay when his mentor seems unable to deal with his friend Ben's (guest star Brendan Fraser, "The Mummy") potentially fatal illness. Meanwhile, Turk (Donald Faison) is upset at the news that he isn't the best surgical intern on the team, but he's even more frustrated when he finds out who is; Dr. Kelso (Ken Jenkins) asks Elliot (Sarah Chalke) to write a supposedly anonymous evaluation of him -- but the joke's on Carla (Judy Reyes) when she volunteers to ghost-write. Christa Miller ("The Drew Carey Show") play's Cox' ex-wife and Ben's sister.