Kristin Lehman guest stars on this Monday's episode of Castle - and it's safe to say she makes an impression on both Kate and Castle.

The actress will portray Serena Kaye, an insurance investigator who has no problem inserting herself in the latest case, standing up to Beckett and flirting with Rick. But is she also hiding a key secret from the team?

Watch the official preview for "Eye of the Beholder" now, following by a pair of sneak peeks at Lehman's character and our favorite tandem's reactions to her:

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