Three days before Christmas the body of a bearded man in a tailor-made Santa outfit turns up in a sewer; Brennan visits her father in prison and plots a nontraditional holiday reunion.
After construction workers find an archbishop's body with the kneecaps surgically removed, the team returns to the case of the Widow's Son serial killer.
Addison treats two pregnant women who unwittingly share the same husband; Violet confronts Charlotte about her liaison with Cooper; Dell reveals a special woman in his life.
The team reopens the 1981 case of a yuppie couple's murder; while investigating, Lily discovers that the couple's friends had ties to a '70s radical activist group.
After finding a ghost's daughter, Melinda realizes she must help them acknowledge their shared past in order for the mother to cross over.