The “Castle” Season 6 finale, “For Better or Worse,” has cast “Warehouse 13” star Eddie McClintock to guest-star in the episode.

McClintock made the first announcement of his upcoming role via Instagram, posting a photo of himself with a “Castle” sign and the caption: “So this is happening. #CASTLE #YIPPEEEE”

TVLine added the information that McClintock will play the role of Rogan O’Leary, a small-town hustler who has a “complicated past” with Beckett and a reputation for lying and cheating.

The important question to ask about the guy is this: Will he do anything to derail a possible Castle-Beckett wedding in this finale? Or does he have another role to play.

“Castle” airs Mondays at 10 p.m. on ABC, while “Warehouse 13” returns for its finale season on Syfy April 14.

Posted by:Laurel Brown