The son of a self-made millionaire vanishes on his way to school; a rebel investigator must retrieve the victim.

The Cain family receives a parcel that suggests more of the children may be in danger; Knapp goes to Brown University to look for Aubrey.

The Cain family hosts the annual charity ball to prevent the public from discovering that Leopold has been kidnapped; Conrad Cain confronts a former childhood friend who appears unannounced.

Special Agent King senses that something is wrong as Virgil is prepped for surgery; Knapp goes under cover to find the origin of the specialized bullet that struck Virgil.

Knapp and Special Agent King investigate the remains of a burned-down textiles building, where the room was carefully rigged to detonate on command.

Ellie Cain's father (Robert Foxworth) negotiates to get his grandson back; Knapp and King uncover information about the Cain family's past.