Matt and his friend Henry (guest star Andrew Leeds) critically injure one of their fellow high schoolers in a hit-and-run car accident while under the influence of marijuana, and Matt later discovers that the girl's strict Christian Scientist mother (guest star Alyson Reed) refuses to allow surgery to be performed on her now-disfigured daughter. Christian connects with a fellow victim of childhood sexual abuse (guest star Katy Selverstone). Grace discovers Sean's affair with Megan (guest star Julie Warner). A priest (guest star Jamie McShane) conceals his identity by having Christian remove an incriminating birthmark.