Inside Man follows a former professor of criminology (Stanley Tucci) who finds himself on death row, spending his last days working on unsolved cases. Meanwhile, a vicar (David Tennant) has trapped a journalist (Dolly Wells) in his basement. In a cascade of monumentally bad decisions carried out by both men, their lives unexpectedly cross paths. This limited four- part series, currently streaming on Netflix, was created by Steven Moffat (Doctor Who, Sherlock), who was in attendance at a Q and A at the recent BFI London Film Festival following the screening, alongside Stanley Tucci and David Tennant.

Moffat began by explaining how he came up with the idea for the show. “I had three notions in my head. One, how would I negotiate my survival if I were locked in a basement with a secret that no one wanted to know? I don’t know why I think that’s going to happen to me, but I think it might, and I want to be prepped for it. The other was, could I possibly ever kill someone? And, would I kill an innocent person for money? I’m very confident that I would not do that, but would I kill a person to save my own life? Kick him out of a lifeboat? Maybe. I wouldn’t admire myself for it, I hope I’d be more heroic, and I would at least aspire to not be that man. And finally, would I kill an innocent person for my child? Yes! And that’s the gaping hole on the side of morality, isn’t it?”

Speaking of morality, two-time Golden Globe-winner Tucci, weighed in on his character’s darker instincts. This is not the first time the actor has played a violent man, including his turn as a serial killer in The Lovely Bones (for which he earned a Golden Globe and Oscar nomination), though this character is one of the more ‘likeable’ and ‘charming’ killers in his litany of baddies.

“There are lots of them out there. It’s obviously one of the reasons I was so attracted to it. Not only because it was Steven writing it, and the cast, but the character was a real dichotomy. And the fact that he acknowledges what he’s done, and as he said, he wants to do something that’s of moral worth. So, it’s not this denial of his actions, because he completely accepts it. It’s bizarre. It was bizarre to read and exciting to read. There was no way I wasn’t going to do it.”

Tennant’s man of the cloth carries out some alarming wrongdoings, particularly given his occupation. “It was that thing of going, ‘Oh no, don’t make that terrible decision, and then don’t follow it with that terrible decision.’ Yet at each step the plausibility is there, so you can see [how it happened]. And that’s what I think is terrifying as a viewer. You can think, ‘I can kind of see how I could end up down this terrible dead-end alley.’ And then the further down it you get, and that sort of mounting asphyxiation you feel as you read it, that made it terribly appealing to be part of that story, of course.”

What makes the story so compelling is the infusion of Moffat’s violence with a dose of dark humor. “I think that’s life, isn’t it? I think at our darkest moments we can find things hilarious. I think it fizzes with reality when you can combine those two things.”