House believes a patient's (Howard Hesseman) seizure was caused by an infection, but the man's sudden heart attack forces the team to change direction and opt for a heart transplant.
Paul stands in the way of Susan receiving a kidney transplant; Tom passes up a lucrative job to continue working with Carlos; Andrew's alcohol consumption increases, worrying Bree.
Audrey claims that she saw a ghost.
A visit by J.D.'s older brother Dan causes them to re-examine their relationship. Dr. Cox teaches Turk how to separate his feelings for his patients. J.D. and Turk end up spending Halloween night at a bar.
Kitty's life is in jeopardy as the Walkers frantically search for a bone marrow donor.