When the assistant to Modern Fashion Magazine's dictatorial editor Matilda King is found murdered, Castle and Beckett are thrust into the glitzy, ruthless world of high fashion in their search for the killer. Meanwhile, Beckett's history in the modelling world gets her access to a very special wedding surprise.

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.