S1, E18: J.D. (Zach Braff) suffers from guilt-induced insomnia after Carla (Judy Reyes) points out that he avoided a terminally ill patient because the man was a difficult pill. Meanwhile, Dr. Cox' (John C. McGinley) ex-wife Jordan (guest-star Christa Miller) interferes in his new relationship with medical student Kristin (guest star Kelli Williams, "The Practice"), and Turk (Donald Faison) and Elliot (Sarah Chalke) obsess over evidence that Dr. Kelso (Ken Jenkins) might be concealing a musical past.