Caslte and Beckett investigate the murder of a model during Fashion Week.
Turns out the girl not only had a stalker but was being blackmailed for sex by her photographer. In the end it was her husband who stabbed her believing she'd cheated on him even though she hadn't.
Castle meets an attractive young model only to awkwardly realize that she used to be the teenaged girl who babysat Alexis.
Ryan and Esposito uncover that Kate worked as a model when she was 17. She says she hated the life and quickly quit. She threatens them with bodily harm if they show the pictures to Castle.