Laura Prepon has landed a key, confusing role on Castle.

The former That 70s Show star will join the series later this season as Natalie Gray, the actress who will portray Nikki Heat in the big screen version of the novel "Heat Wave." Follow all that, fans?

Castle, of course, based Heat on his crime-fighting partner, Kate Beckett. So it should be interesting to see how he responds to the woman who will be playing the woman that is based on the woman he loves. Know what we mean?

Prepon most recently appeared on episodes of How I Met Your Mother and House.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.