Nikki Heat

Natalie Rhodes (Laura Prepon), playing Nikki Heat in the film adaptation of Heat Wave, joins Castle and Beckett in their next investigation of a high class match-maker, Stacy Collins. Natalie goes to extremes during her "character research," making herself into the exact image of Beckett, much to Castle's delight and Beckett's dismay. Ryan tries to find the best way to propose to Jenny.