Adam Baldwin is coming back to ABC's Castle and now we know the reasons surrounding his return.

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Baldwin is returning as Detective Ethan Slaughter in the next episode of Castle, slated for Nov. 9. The episode, titled Cool Boys, features Detective Slaughter getting Castle (Nathan Fillion) to help him in a robbery case.

ABC's new plot synopsis for the episode reads as follows:

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"Detective Slaughter (guest star Adam Baldwin) returns to enlist Castle's help in solving a high-stakes robbery case. But when a body is found linked to the crime, Slaughter becomes the number one suspect in the heist turned murder, while Castle has to determine whether he's guilty or help to prove he's innocent."

Baldwin first appeared as Slaughter in a season 4 episode of the show. Fans should delight in seeing Fillion and Baldwin together again, as both previously starred in Fox's short-lived but beloved sci-fi western series Firefly,

New Castle co-showrunner Alexi Hawley recently spoke to Baldwin's return as Slaughter and how they are planning something a little different from his first appearance.

"Given everything that happened in season 4 between [Slaughter and Castle], obviously Castle's very hesitant," Hawley told Entertainment Weekly earlier in the month. "But we want to do something unexpected with it, to turn the story a little bit on its head, so it's not going to be just a carbon copy of the episode we had before. We have some really great twists and turns."

Castle airs Mondays at 10 p.m. ET/PT on ABC.

Tags: Castle television ABC