As the rest of team looks into the death of a toy company's CEO, Castle starts his own investigation after finding a lead in his mysterious disappearance.
While Johnny tries to get a grip on his feelings, Charlie must try to bond with a bank robber.
A missing FBI agent is found dead in an investigation that forces Pierce to face a past unsolved case, and Pierce's therapist grows concerned that the investigation may exacerbate Pierce's condition.
Pierce witnesses the death of a gallery owner, but he comes to believe it was actually a murder. Pierce and Moretti try to hunt down the killer, only to end up in the middle of a daring art heist. Meanwhile, Pierce analyzes his relationship with Natalie.moreless
Jed meets a woman who also "was in treatment", and they become romantically involved. Kate is very nasty to her. Meanwhile, Kate is having an affair with one of the tenants. Ryan meets a mysterious woman who lives in the basement and collects information about missing people.moreless