In season 3 "Nikki Heat", Castle is upset when B-movie actress Natalie Rhodes is cast as Nikki, thinking she is not right for the role. When Rhodes comes onto a case to observe Beckett, Castle is further insulted that she has not read the actual book. Rhodes considers him unimportant to the film and Beckett likes having Natalie around. However, as the case goes on, Rhodes begins to copy Beckett's mannerisms and outfits, complete with brunette wig, annoying Beckett while Castle begins to like her more. At one point, Rhodes kisses Castle, making it clear she wants to sleep with him to feel the character more but Castle turns her down, telling Beckett that sleeping with the actress playing the fictional version of her is "way too meta".