When a guilt-ridden young woman confesses to the murder of a struggling actor—knowing details only the killer could know—Beckett and Castle seem to have an open-and-shut case, until they uncover proof that their suspect couldn't possibly be the killer. When a second person confesses, equally convinced they committed the murder, the team realizes the case is far more mysterious than they thought.

When a Japanese ballet dancer is mysteriously murdered, Castle and Beckett's investigation into her secret life uncovers evidence that she was killed by a ninja, and now that ninja is coming after them.