Jennifer Riker

When an Arctic explorer is killed during a polar expedition, the mysterious circumstances of his death take Castle and Beckett from the penthouses of Park Avenue to the halls of the CIA.

After a series of suspicious murders occur, Prentiss suspects her old Interpol nemesis, making her fear for the safety of her BAU team as he closes in on her.

When Monk and Natalie get stuck in a small desert town, he must uncover the link between a missing woman and a UFO sighting.

The red cell team hunts a serial killer who has been traversing the country kidnapping and then hanging his victims.

Martin decides to take a chance and spills the beans to Detective Lange in hope of clearing his name; Jake leads Avram to a possible Righteous 36 member.