Castle went all sci-fi on viewers this week, dealing with a killer who claimed to also be a time traveler.

Next Monday, meanwhile, the show will once again travel to the future - but in a different sort of way.

Yes, Halloween will arrive a few days early on this ABC smash, with Castle and Beckett looking into the strange murder of a young woman they find ritually posed, a collection of odd symbols strewn about her apartment.

Look for the main suspect to be a mysterious monk and for Castle (of course) to be convinced that the team has come across some kind of DaVinci Code-style conspiracy.

Check out the official promo for this Castle Season 6 episode below, followed by a number of photos from "Get a Clue" that feature Rick, Alexis and Pi:

Castle Promo: "Get a Clue"

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