Adam Baldwin guest stars on this Monday's new episode of Castle - and while that may be exciting news for fans of Firefly or Chuck, it's less than thrilling for Kate Beckett.

That's because she gets the feeling on "Headhunters" that she's being replaced by Baldwin's Detective Slaughter, a feeling Rick doesn't do a lot to discourage, not when he's still recovering from Beckett's lie over what she heard him say on last season's finale.

Check out two clips from the upcoming episode and then continue to look ahead via these Castle photos, which depict our favorite duo tracking down some seriously unusual (undead?) suspects...

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