03/20/2013 09:04 am ET Updated Mar 20, 2013

'Supernatural': Misha Collins On Castiel's Mission, Sam And Dean's Distrust, And 'Goodbye Stranger'

Misha Collins returns to "Supernatural" in this week's episode, "Goodbye Stranger" (9 p.m. ET on The CW), and from the outset, the actor promises, we'll "see why we should not trust Cas."

HuffPost TV talked to the newly promoted series regular about Castiel's "strained" relationship with Dean (Jensen Ackles) and Sam (Jared Padalecki), the role Crowley (Mark Sheppard) will play in the episode and more. Warning: Light spoilers ahead.

What has Castiel been up to since we last saw him?
Well, Naomi [Amanda Tapping] has been continuing to program Cas as something of a "Manchurian Candidate" and that programming process has been quite thorough, and fairly successful, as well. So we begin the episode with the Frankenstein Cas complete and ready for action.

Sam and Dean clearly don't trust him at this point. How does Cas react to that? Does he trust himself, or does he have some awareness that he's being manipulated by Naomi?
I think that Cas is slipping in and out of awareness that he is being controlled, and for the most part, is unaware of it. It’s something that’s definitely operating in his unconscious, but it’s a little bit of a blurry line as to how much or whether he understands that he’s being controlled. However, it’s out in the open that the boys don’t trust him in this episode, pretty early on, and they, nonetheless, all have a shared objective, and they all go after it. Knowing that they don’t trust one another, it’s sort of another deal-with-the-devil situation for the boys, where they kind of need Cas’ help, and so they take advantage of it, even though they don’t trust him.

We've also seen Dean praying to Cas this season, so although he knows there's something off about him, is that indicative of the fact that he still trusts him enough to ask for his help?
Yeah, although "trust" is a strong word to use. I don’t think that Dean really trusts Cas at all. I think that he knows that Cas is potentially a valuable tool, and he’s very carefully using him as a tool to achieve these objectives. But it’s certainly a very, very strained and tenuous relationship at this point. And right away, from the opening scene, we see why we should not trust Cas. The episode is set up with Cas as being a fairly untrustworthy collaborator.

What can you preview about Castiel's showdown with Crowley this week?
I think this entire season is about a showdown with Crowley, in one way or another. This episode certainly has a good showdown, and then there are more showdowns to come down the road. The battle continues.

What can you say about Meg's (Rachel Miner) involvement and how she ties into the trio's quest?
Well, Meg has been captured by Crowley and has been tortured by him for some time. I don’t know if I’m supposed to be talking about that, but I am. She ends up having quite a bit of information on the mission that the boys and Cas are after.

After Samandriel's (Tyler Johnston) death, it seems like we could be heading towards Naomi asking Cas to do something like taking out Sam and Dean. At this point, would he be strong enough to fight that order, or has she got him pretty thoroughly controlled?
I mean, honestly, knowing the characters as well as I do, I would hope that if someone asked Cas to kill Sam and Dean that he would do it. I mean, just do what you’re asked! Do what you’re told. [Laughs.] I think that it would be without dramatic merit if Cas were told to do something like take out Sam and Dean and were to do it without any struggle. So I’m sure that there will be some sort of tension around any programming conflict, with Sam and Dean.

Throughout his arc, Cas has always struggled with the concept of free will versus following orders. Do you think he's heading towards a place where he might finally get some agency as a character?
Well, I know what happens, so I could tell you. But I won't. But I will tell you that the struggle with free will does become central.

We now know enough about the demon tablet and what it means for the future of demons to hypothesize that the angel tablet might mean similarly bad news for the angels. What do you think Cas' feelings on the angel tablet and its effects would be, were he not being controlled?
You ask such pointed questions -- I think you want the mysteries of this show to be ruined for everyone. I feel like you’re goading the witness right now, and I don’t appreciate it. Needless to say, I think that everyone is aware that the angel tablet is a very important stone document. [Laughs.]

He was obviously very reluctant about returning to heaven even before Naomi started brainwashing him, so I can't imagine he'll have positive feelings towards it afterwards. Do you think there's a part of him that would forsake being an angel if he could?
I don’t know. I mean, he’s still struggling with his guilt and remorse with regards to heaven. While he has been in conflict with the angels -- and many of them have been doing fairly unsavory things to him -- he also feels like he owes the angels and heaven a debt and that they are his brothers. So there’s a part of him, the idealistic part of Cas, I think, that never really gives up on heaven.

Lastly, what's coming up for your charity, Random Acts?
We just kicked off our third and final Hope to Haiti campaign. We’re going to be returning in June to Haiti to the Jacmel Children’s Center, which will be totally finished, which I’m really excited about. The photos I’ve been seeing are absolutely beautiful. It has, by far and away, exceeded any of our expectations, and it’s come in under budget and really, really beautifully.

Do you think Castiel will be able to break Naomi's programming any time soon? Where do you predict he'll end up this season? Weigh in below!

"Supernatural" airs Wednesdays at 9 p.m. ET on The CW.