Adrian Rogers, © BBC/BBC Worldwide 2014

'Doctor Who': How The 'Robot Of Sherwood' Got His Hilarious Laugh

Writer Mark Gatiss and actor Tom Riley preview this week's (hilarious) episode of 'Doctor Who'.

This week on "Doctor Who," The Doctor (Peter Capaldi) teams up with Robin Hood (Tom Riley) for what might be the funniest episode of "Who" ever - or at least in a good long while. In advance of the episodes airing on BBC America on September 6, MTV News talked to Riley, as well as writer Mark Gatiss about developing the idea, getting cast, and how they created Robin's hilarious, infectious laugh.

We'll have more spoiler-filled talk with the duo after the episode airs, so tune back in then. Oh, and very mild spoilers for the episode, though nothing you couldn't figure out from the promos.

MTV News: What was the general idea when you were starting? How did you come to the idea of the Doctor and Robin Hood teaming up?

Mark Gatiss: It was Steven [Moffat]'s suggestion. It's different every year. Last year, I always wanted to bring back the Ice Warriors, and I always wanted to do a submarine story, so I combined the two. This year, Steven said, "What about Robin Hood, I've always wanted to do Robin Hood." I always loved the Errol Flynn film in particular, so I thought it could be great fun. The whole of idea of presenting it as too good to be true, as a '30s matinee idol version of a character who wasn't real anyway, was irresistible.

That, in combination with a Doctor that I knew was going to be less human, and a bit edgier… I can imagine that Matt [Smith]'s Doctor would be happier to see Robin, where as Peter [Capaldi] is anything but! [Laughs]

MTV: So who is the Doctor in this episode? As viewers, three episodes in, we're still trying to figure him out.

Gatiss: It became early on a debate about heroes. The Doctor is so determined to prove Robin Hood can't be real, he misses the point that he is as much as a fantastical creation as Robin is. Clara looks up to him as she does to her childhood hero Robin Hood, so it was a quite a nice thing to play with. At the end of these three episodes, he's asking the question, "Am I a good man? I've made mistakes. Who am I, really?"

There's no clear solution, he's always sort of bumbled along. But I think by the end of this episode, we the audience are a bit clearer that he knows where he is again.

MTV: Tom, Robin Hood is such a completely different character from Da Vinci on "Da Vinci's Demons." How did you get cast in the role, and what was it like creating this take on Robin Hood?

Tom Riley: It was great fun to do. When the offer came through, it was one of those things that rather than, should I do this, it was, I have to do this. We made sure the scheduled was free, and the gap was going to work. On the page, it came across as absolutely hilarious anyway, but once I talked to Mark over a cup of tea, he talked about how he saw Errol Flynn in the movie, and I had seen it a long time ago but went back and refreshed myself on it.

I was absolutely fascinated by how out and out shamelessly heroic Errol Flynn played it, and unapologetic, and full of joy. As far as The Doctor was concerned, the Peter Doctor, it was going to rub him the wrong way, and that was an absolute blast to play.

Gatiss: What's very nice, and what emerged as we did it is the idea of how much front he has, that he's doing for a purpose, that he's being a hero because that's what people need. And underneath it he has a nice backstory. He's lost Marian, he needs to prove himself. But Clara sees through him instantly, I love that scene in the camp where she says, "The Doctor is right, you're laughing too much." It is for a reason. He's not just a cardboard hero, he knows why he has to behave like this for the people around him.

Riley: It's that stuff in the script that lets you lean to the more outlandish side of his personality, because I was aware that he was more character than caricature. That gives you freedom, liberty to play knowing that he's rooted in something completely real, as well as seeming impossible.

MTV: I wanted to ask about the Robin Hood laugh, actually, because it's amazing. How'd that get developed?

Gatiss: When I watched the film several times in preparation, it struck me straight away. They laugh at the drop of a hat! Literally. They laugh at the drop of a hat. I just thought it was a really funny idea that the Doctor would go, "Stop doing that! Are you simple or something?"

So then it becomes a sort of motif, and the Doctor finds it becomes infectious, The Doctor is bantering and he hates it. But Tom developed that laugh, and its excellent.

MTV: So did you try any other possibilities, Tom? I don't know how we'll get this across in a text piece.

Riley: [Laughs] Oh man. I tried the Errol Flynn, and I saw that very deep, hearty, inclusive laugh, and thought, well, that's what it is, isn't it? It's infectious, and as long as everyone around plays in, as the Merry Men did, all laughed as much as Robin, then it'll work.

I was going to go for a thin, reedy, creepy one, but it just didn't play. [Laughs]

"Doctor Who" airs Saturday, September 6 at 9 p.m. ET. Head back to MTV News right after the show for more from Gatiss and Riley.