Credit: Richard Foreman / ABC Television Group © 2012 Disney Photo: Detective Ryan Appears Worried in Castle Season 5, Episode 15: "Target"

In an earlier Castle spoiler, we told you that squeaky-clean Detective Ryan is getting an episode that’ll explore his past. Now, TVLine has exclusively learned who’s going to be playing this “blast from the past,” and you won’t believe who it is!

None other than Mad Men’s Cara Buono will guest star as Siobhan O’Doul, a Staten Island tavern owner with ties to the Irish mob and Ryan!

According to TVLine, when the detectives investigate a murder case tied to the Staten Island mafia, it leads the team to O’Doul — a woman who “shares a mysterious past with” Kevin. Hmm...

Wait, the same Ryan who’s married to Jenny, and bobbing for babies, is connected to a mafioso? Isn’t that juicy!

The episode doesn’t air until March, so we’ll have to wait ‘til then to get a whiff of Kevin’s dirty piece of laundry.

Are you interested in learning more about Detective Ryan’s past? Tell us below!

Source: TVLine