Castle Season 4 Spoiler: Seamus Dever Reveals His 1940s Alter Ego in Episode 14, “The Blue Butterfly”
Castle's upcoming 1940s film-noir flashback episode,"The Blue Butterfly," sounds better and better with every passing spoiler.
As we already know, the entire cast will travel back to New York City's Golden Age in a flashback that mirrors a case the 12th precinct is investigating in the present.
In a cool twist, their flashback alter egos are the exact opposite of their modern-day counterparts, which means we'll get to see Castle as a detective and Beckett as a bad girl.
But what about the rest of the cast? Seamus Dever recently dished to The Hollywood Reporter that Detective Ryan will take on the role of a "tough-ass guy with an Irish accent."
Thankfully, the new role didn't interfere with his sense of humor. While filming at the Park Plaza Hotel in downtown Los Angeles, Seamus and his Castle sidekick, actor Jon Huertas, played a prank on co-star Nathan Fillion.
"They have a dirty basement that Nathan and Jon and I explored. Nathan went down there on his own but Jon and I snuck up behind him," he laughed.
"Jon used his special forces skills and we scared the crap out of Nathan. It was awesome."