As Christmas approaches, Bull is amused when he meets a 9-year-old girl who wants to hire him to help her divorce her parents, but he's shocked when a judge appoints him her temporary guardian. Also, Marissa discovers disturbing information about her boyfriend, Kyle.

Bull takes a psychologist friend, Dr. Donovan Benanti, as a client when the therapist is sued for malpractice following a patient's deadly rampage. As Bull worries a trial loss could set new precedent regarding doctor-patient confidentiality, he aims to convince the jury that clinicians aren't directly responsible for their patients' actions.