Each year the Global Slavery Index releases the number of people living in modern slavery around the world. In 2016, an estimated 11,700 people live in slavery in the UK alone. Panic highlights this crisis on our doorstep

We watch blockbuster upon blockbuster about human trafficking: Liam Neeson going to any length to save his daughter after she’s taken in Paris, Scarlett Johansson fighting a Korean drug cartel in Taiwan.

It’s very rare that we get a glimpse at the people who have been enslaved on our doorstep.

Sean Spencer’s neo-noir thriller, Panic, shows just how close to home trafficking really is.

“I was in a pub with one of the producers and a middle-aged Chinese man came in and spoke to a few tables really quickly,” say Spencer. “It was clear that he was trying to sell DVDs. That was the spark of something: I just wanted to know more about what that guy’s life was like.”

Filming in the Arden Estate and St John’s Estate in Hoxton, Spencer spent the previous months speaking to various sources to inform his writing, including journalists, refugee charity workers and someone who had worked in a brothel in London.

“I wanted to explore London’s intricate and often brutal ghost economy, at the point where migrant labour reached the criminal underworld. I was also interested in looking at how people live in big cities, with that feeling a lot of people have of dislocation and social alienation.”

Panic tells the tale of music journalist, Andrew Deeley, whose psychological scars from a vicious attack are preventing him from leaving his high rise flat. He spends his days listening to records and interviewing musicians and his evenings staring at the beautiful woman in the flat across the street, Kem. When she is kidnapped, he must face his fear of the outdoors and find out where she is.

It might sound like the same old unlikely hero story, but Deeley’s anxiety and regular panic attacks keep the film grounded. It isn’t hard to imagine every inch of this being true.

“I wanted to keep all of the action ground level, ultra-realistic,” he says. “He’s a journalist so he has certain skills in terms of looking for information but he’s not got any other skills: he’s not a fighter, he’s not a detective.

“In the world of what’s real and what would I do and what would anyone do in that situation, it came down to just an oyster card and a hammer.”

Deeley is played by David Gyasi, best known for his roles in Interstellar, Cloud Atlas and BBC’s White Heat.

“He had spent quite a few years playing the supporting actor and wanted to play the lead, so he was ready to carry a film and I totally believed that he could do that,” Spencer says.

“He’s a very open, emotional actor. You’d think most actors are emotional but many aren’t; many are more intellectual and approach their work in that way. He’s all from the heart and that’s what makes working with him really special.”

While the crux of the story is Deeley’s pursuit of Kem, Gyasi’s portrayal of his isolation is what will give the film its hook for many viewers.

“It’s a statement about the way society’s changing and the way we live now. Especially with people who live in areas that have a bit more crime than others, as soon as they leave the house they don’t make eye contact. When they come home, they leave the station, take a breath and don’t breathe until they get to their house.”

But it’s not just about danger, London’s anonymity and “shifting values” mean that “we don’t actually need to communicate with anyone when we leave the house, if we don’t want to.” Deeley’s agoraphobia is an extreme manifestation of the way a lot of us feel in a crowded city at some time in our lives.

The tension and isolation in Spencer’s script is heightened by Christopher Nicholas Bangs’ score, which captures “that feeling of alienation, of that unsettled and uncomfortable feeling throughout.

“I wanted to subtly disturb the audience and locate that sense of confusion and paranoia, while drawing the audience into Deeley’s deeper internal state as he slowly starts to unravel.

“Chris said a really interesting thing the first time we met. He said it had to feel like blood in your mouth.”

Panic is released Nov 18, with screenings at the Crouch End Arthouse until November 20, with a Q&A on Friday Nov 18. It shows at Genesis on Nov 26 and Dalston Rio with a Q&A on Dec 4.