Castle‘s mob ties are about to be exposed.

The ABC procedrama is planning a mafia-themed outing during November sweeps featuring guest turns by Patrick Fischler (Lost, Mad Men) and Tony Denison (The Closer/Major Crimes), TVLine has learned exclusively.

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In the episode, Fischler plays Leo Conrad, a mild mannered witness to a murder who Castle and Beckett take on the run to protect him from a 
team of ruthless gangsters who want him silenced.

Denison’s character, Mickey Dolan, is an enforcer with the McElroy 
crime family who was friends with the victim until recently when they
 had a falling out.

The ep, cheekily titled “After Hours,” is set to air on Nov. 19.