Kit Harington is a little worried that his new TV show is too like Game of Thrones

Then, turning on his heel, he strides away – and then the director calls cut, Harington’s beard gets a quick brush-up and everyone resets for the next take.

But while the beats are familiar, I’ve not just stumbled upon some secret filming for Game of Thrones season 7. Rather, I’m knee-deep in mud (shipped in to the set specially) for Harington’s brand-new drama Gunpowder, which aims to tell the untold story of the men behind the fmous Gunpowder Plot who WEREN’T Guy Fawkes (including Harington’s character Robert Catesby, actually his own ancestor).

Still, Harington acknowledges that people might notice the similarities between Catesby and his most famous role as Jon Snow, aka Aegon Targaryen, aka the moodiest teenager in Westeros, which brought him fame and fortune in the aforementioned HBO series.

“There was a certain level of this being in a cloak and with a sword and all of that, and I thought 'here we go again.'” Harington says in a free moment on the set, where he’s performing dual roles as actor and executive producer.

“But maybe I love it, I don't know. Maybe I secretly love it and this is the thing I wanna do forever.”

He adds: “In some ways you could see [Catesby] as a sort of troubled, angsty, emo-ey sort - and we've all seen that before. But he's not that. He's much darker. He's got a real demon inside him that he's trying to exorcise in some way.”

Still, the strictures of Game of Thrones did give one advantage to Gunpowder’s production, with the HBO series’ famous rule about Harington’s hair (which fans and certain TV listings websites have been known to use as clues for series storylines) feeding into this time period.

"This fitted quite well into not being able to cut my hair!” he joked at a recent screening for Gunpowder’s first episode. “Why I keep ending up in cold, muddy places, on horses, I've no idea. It must be some desire that's built into me from a past life, I think.”

"I'm personally done now with [that] so moving forward, [I'd like] something with guns! Just move my way slowly more modern, century by century."

For now, though, he’s firmly in the past, telling a story known to almost every schoolchild in Britain – though as Harington and other cast members noted, a tale of oppressed religious fanatics trying to enact change through violence could hardly be more relevant to the here and now.

“Tragically, whenever this was made it'd be relevant,” Tom Cullen, who plays future straw effigy model Guy Fawkes in the drama, tells press on set. “I feel like what this is doing is showing that the human condition never changes.”

“The idea that people are fighting against a system that is keeping them down is relevant across the world in so many countries,” agrees Sean Dooley (who plays torturer Sir William Wade). “It's frightening how relevant it is.”

“That's one of the reasons we're making this,” Harington adds. “We don't want to make a historical drama that has no resonance with today. We absolutely want to make a drama that people will relate to when they watch.”

And Harington’s also hoping that the drama can also educate people on the real story behind the Gunpowder Plot, which he believes has been oversimplified by history.

“When you ask people about the Gunpowder plot, they say ‘Guy Fawkes.’” Harington says. “And some of them don't know whether the Houses of Parliament were blown up or not.

“I felt there was a story here that people would want to watch. That they might not know about, that they might learn about through this production.”

And following Gunpowder and the last season of Game of Thrones (whenever it actually arrives), Harington says he’ll be happy to hang up his sword, shield and insulated capes for good – to the extent that he doesn’t even look at scripts with a hint of medievalism in them.

“I think people have stopped now sending me certain roles, because I just don't look at them if they're too similar to the role that I'm known for,” he says.

So what’s next – some sort of happy, sunny role in a Hollywood romcom?

A very non-Jon Snow smile appears.

“Maybe not a romcom?” Harington says. “I've gone out for a few romcoms, I dunno - I'm just not a rom-commy person. I'm really not.”

Rubbish - we're sure with a new set of clothes, a shave and a haircut anything’s possible.

Gunpowder begins on BBC1 this Saturday 21st October at 9.00pm