Devon's doubts about his relationship reach a peak as his friends and family gather for his big wedding day; as Chastain's medical device company continues to succeed, Julian makes a discovery that leaves her uneasy about her involvement in it.
The BAU is called to Oklahoma to investigate a murderous clown who is terrorizing a town.
When a woman is found murdered near a remote men's social club, Jane must find a way to insinuate himself into the insular group of the rich and powerful to find the killer.
Rosewood and Villa investigate the murder of a woman whose body was found frozen solid; Villa's brother meets the important people in her life but isn't ready to have a reunion with his mother.
Nurse Lockwood is arrested for refusing to do a DUI blood test on a patient without his consent; Dr. Halstead discusses his impending lawsuit with his lawyer; Dr. Manning and Sharon Goodwin raise concerns about the nature of a baby's injuries.