The idea for the film came to the director David Gleeson as he was driving past a bank in Dublin. Outside the building stood a security man, whom Gleeson took to be African and whose suit did not quite fit. “He seemed somewhat out of place, but he had this great big smile on his face,” says Gleeson. “I couldn’t help but think that someone was going to give him the once over — this was a rough part of the city — call him a black bastard and ruin his day.”

Driving on, he pondered what sort of life the security guard might have; what material deprivation he had escaped, what pressures may have impelled him halfway around the world to a city in the chaos of an economic boom, what was pushing him from his homeland, what was pulling him here. As Gleeson let his mind wander, he began to imagine a back story for the smiling guard. In the fullness of time, this seed of an idea took him to Congo, where, cooped up in a hotel room, he bashed out a script for The Front Line, the follow-up film to his 2003 debut feature, Cowboys & Angels.

A heist movie of a sort, The Front Line’s vision of Ireland owes more to John Woo than to John Hinde. In it, asylum seeker Joe Yumba (the Cameroon-born French actor Eriq Ebouaney) is given a frosty welcome to Dublin by Detective Inspector Harbison (Gerard McSorley) at the immigration bureau. Claiming to be fleeing persecution from warring rebel factions in his native Congo, Yumba settles quickly into his adopted city. Having landed a job as a security guard at a bank, he is joined by his wife and young son, who arrive on a family reunification visa.

All seems fine until Yumba finds himself the reluctant inside man for a criminal gang led by the psychotic Eddie Gilroy (James Frain). All, however, is not what it seems.

Having made his breakthrough with the coming-of-age tale Cowboys & Angels, the Limerick-born Gleeson and his producer wife, the German-born Nathalie Lichtenthaeler, knew they had to strike while the iron was hot.

“I didn’t want to do a genre piece,” says Gleeson. “I saw The Front Line initially as a thriller, but Nathalie pushed me to lock myself in that hotel room for a week and write a script. I came out with this whole big story, the whole Congo thing. I did have to wonder where that came from, because it’s like a film of two halves. The trick was to hide the seam between the two.”

For anyone looking for convenient signposts, the two halves are Spike Lee’s thriller Inside Man and Terry George’s drama Hotel Rwanda. One problem for Gleeson was that this connection only became apparent in retrospect. “When potential financiers asked me to list movies that The Front Line might be like, I just couldn’t think of any,” he says. “I couldn’t even list any strong influences for what I’d written.”

Gleeson’s influences as a writer and director are not so hard to trace. His grandfather opened up his first cinema in Limerick in the 1930s and his 75-year-old father still works daily in the family business, so it’s hardly surprising that he pursued a career in film or that his taste is populist.

“When I was at my most malleable, movies were all around me,” he says. “I was brought up literally in a cinema. My father ran four cinemas, and while the other kids were in nightclubs, I was working the projector or checking the tickets.

“Steven Spielberg, John Ford: I’ve always been drawn to the big film-makers. Gone with the Wind blew me away when I saw it on the big screen in 1981. [I] wrote down in my diary that night that I was going to combine my love of writing with my love of movies, and become a film-maker.”

As a teenager in the 1980s, he banged out and directed several plays, notably Class Control. However, it dawned on Gleeson that there was little chance of “a young nobody from Limerick making a film in Ireland”, and after failing to get on a film course, he moved to Scotland for two years to study communications.

While there, he took a step sideways: working on oil rigs in the North Sea, with a view to getting enough money together to shoot a short film. And that’s where he spent the next seven years. “I was a twentysomething guy with money,” he says, by way of explanation.

An ad in a movie magazine eventually prompted him to pack his bags in 1995 and enrol on a course at the New York Film Academy, where he met his future wife.