God may have had a long absence from Supernatural, but Supernatural fans certainly never forgot about God.

Sure, Rob Benedict popped up over the last few seasons, here and there; memorably, he made a surprise appearance in the show's meta musical episode. But neither he nor the show addressed the God-sized elephant in the room.

That is, until last week, when Chuck revealed himself to the Big Man — much to the joy of long-theorizing fans whose hopes were finally confirmed.

Below, Benedict talks about coming back to play Chuck in very different circumstances, bringing a beloved piece of Supernatural history with him and what Wednesday's episode will bring for everyone as they prepare to face off against Amara.

MASHABLE: What was it like to jump back into Chuck's shoes?

ROB BENEDICT: It was amazing. It was so fun. This whole thing has been a treat, especially considering that when I was supposed to start on Supernatural Season 4, it was supposed to be one episode and now all these years later it's such a big part of my life, really. We do so many conventions every year, so it was really fun to go back. And to have this great little arc to do and have the fans being accepting of it was the icing on the cake.

You haven't been out of the Supernatural family since Chuck has been gone. When did you learn you were going to have this big arc?

I didn't know for sure until January of this year, and I went up to shoot it at the beginning of March. So I heard rumblings of it at the beginning of the season. There was some talk that somebody's gotta confront the darkness at the end of the season, and most likely it will be God. I had heard rumblings and some whispers and that kind of thing, but didn't really take it seriously. You never do until it happens. So it was really great, best of all worlds that it happened like this. I didn't know for sure until the script was written and the arc was set. I'm just so excited now that I get to talk about it, finally.

The fact that you got to sing in the episode was a cool nod and wink to fans who know you sing and have seen you perform at conventions. Did you ask for that, or was that a gift from [writer] Robbie Thompson?

It wasn't something I asked for. I think a lot of that is Robbie is also a fan and totally gets it, and I think he writes episodes that the fans really appreciate. Even his scripts, they say things like, "the samulet," which is a word invented by the fans. So, no, that was him.

'I'm just so excited now that I get to talk about it, finally,' says Benedict of returning to 'Supernatural.' Image: Katie Yu/The CW

Speaking of the 'Samulet,' were you as excited as fans were to see Dean's amulet again? They left it a little ambiguous at the end about where it had been. Chuck had that line — "you'll never know where it's been this whole time." And he had it in his hand, but then it popped up in Sam's pocket. Was it in his pocket, or somewhere else?

I think Robbie wants it to be a little ambiguous. I think he still wants there to be some mystery around certain things. Metatron kind of interrupts me, and I never finish that thought. But we were aware of how big that moment was. Definitely even as I was playing it, I was thinking, 'This is huge. We haven't seen it in a while.' And the fact that we answered the question about why it didn't glow in front of my the first time and stuff like that.

In terms of this week, preview for me where we find Chuck in Wednesday's episode.

I think it's clear now there's a job to be done. I've got to confront the darkness at some point, but the first thing that needs to be accomplished is that I got to set things straight with Sam and Dean and convince them I am who I say I am, and not just Chuck. So I think that's the first thing that needs to be addressed. I need their confidence, and need them to understand and know that's who I am. We've got a job to do.

How does he go about that? It sounds like it would make for a really personal episode.

It's both. There's some fun stuff in terms of convincing them that it's not just Chuck being weird.

Which is also a possibility.

Exactly! But Chuck's still Chuck, and he's still a quirky character and that's not gone. So it's still that balance between Chuck and God. He's God when he needs to be God. But absolutely, there are a couple of scenes that are really personal scenes, and I've definitely got a lot of explaining to do to the two boys. So that's sort of what gets addressed.

Since you hadn't played Chuck in a while, what did you bring to the character in the last episode to show the audience how he's changed and what he's been through since we last saw him?

I think the biggest change in playing it this time was we were coming out with the fact that he's God and that he's been playing this role to kind of disappear and be incognito. So getting to show Chuck being Chuck — literally where he's been, that he's created a blog, joined Snapchat, traveled the world, that he's had boyfriends and girlfriends. But the big change was that when push came to shove, he turns and he can be God. So I had to really show that in these couple of scenes in last week's episode. I've never had to do that before. I've never had to be wrathful or anything like that. I've never had to smite before, so I've been doing some smiting, which is new for me. That was certainly fun as an actor to do — to switch back and forth.

The memoir will have to wait, Chuck. There's kind of a big problem afoot. Image: Katie Yu/The CW

It's like that super fun uncle who suddenly yells at you for horsing around.

Right! It's like, 'That's wacky Uncle Chuck! Why is he yelling?"

'Why is he smiting?'

[Laughs]

Lastly, how would you say his relationship with the brothers is different in this episode?

I think there's a new level of trust and love between them, and obviously they've got bigger fish to fry now than they ever have before. The stakes are extremely high. So it goes deeper than it has before because the obstacle ahead of them is bigger than it's ever been.

This interview has been condensed and edited.