Love her or hate her, brazen CIA agent Sophia Turner gifted Castle fans with one little nugget of goodness before her shocking demise: Richard Castle’s dad is somehow connected to the CIA. Er, if we believe her, anyway.

Either way, this new pearl of wisdom has re-opened one question in our minds: Who should play Rick Castle’s dad, should he ever decide to grace the show with his presence?

Originally, we pegged classic macho man William Shatner, the oft-intimidating Donald Sutherland, and the ruggedly handsome Clint Eastwood as Rick’s potential pops. Now, knowing that his dad may also have been a clever, cunning technology whiz who somebody decided was decent enough to trust with the most highly classified information about the United States, well, that opens up all kinds of new doors, don’t you think?

Here’s a few more men we think could play the father of the most wonderful crime-writer-turned-faux-cop we know. OK, the only one. Then, tell us who you’d cast to play Castle’s dad in our poll below!

1. Alan Rickman

Who doesn’t think that Mr. Rickman, better known to younger generations as Harry Potter’s Professor Severus Snape, would make a killer CIA agent? He’s tough, intelligent and gives off just the right amount of mystery and creepiness to keep us intrigued. As for being handsome? Maybe not so much. But it’s the inside of the man that counts, right?

2. Al Pacino

Pulling out the big guns with this one! Award-winning actor Al Pacino is a legend in his field. He’s played both mobsters and the men who catch them with ease. He’s all the things we imagine Castle’s dad to be: tough, gruff and, of course, handsome as hell ... in that guy-who-might-kill-you-in-your-sleep sort of way. Oh, in a perfect world ...

3. Ben Stein

This 67-year-old actor, writer, lawyer, and political commentator is clearly a man who can wear many hats, just like Castle’s dad probably did. He also has that weird, dry sense of humor that only a Castle could appreciate, and that low, monotonous tone we often imagine really smart people having. CIA agents do have to be smart, right?

Although we don’t know if he’s enough of a looker to have wooed Castle’s pretty mama Martha Rodgers, Stein has an undeniably quirky charm.

4. Christopher Walken

Once upon a time, Rick Castle did a pretty stellar Chris Walken impersonation , and we could totally see the Pulp Fiction star as the one who brought Castle to life. Generally typecast as the bad guy, Walken comes off as strong and confident. But as we all saw in Fatboy Slim’s 2000 video for “Weapon of Choice,” he’s also got a silly say. Plus he’s pretty cute, for an older dude, which is obviously the first requirement.