The spying game is a broad church, able to accommodate everybody from George Smiley to Maxwell Smart. And Tony Mendez's story sits right in the centre.

But, unlike Smiley and Smart, he is a real person - a former CIA operative who extracted six American hostages from Tehran in the wake of the 1979 Iranian revolution in circumstances that compounded potential tragedy with broad farce.

Let's start with the tragedy. The Iranian hostage crisis is remembered mainly for the Carter administration's failed bid to rescue the 60 American nationals imprisoned by the Revolutionary Guard after its attack on the US embassy. In the US military's attempt to get them out, eight commandos and one Iranian civilian were killed and two aircraft were brought down, leaving most of the hostages to spend another nine months in captivity.

The adventures of Mendez and his lucky six remained a secret until the case was de-classified in 1997. And it wasn't until 2007, when a magazine article was published, that George Clooney's production company picked up the story, with Ben Affleck signing on as producer, director and star.

Affleck plays Mendez, who hits on the bizarre yet curiously logical idea of getting into Tehran by masquerading as a Hollywood producer with hopes of shooting a movie in the country. He carries forged passports for the six Americans, who have been secretly given refuge in the Canadian embassy. The passports will provide them with false identities as members of the producer's film crew. The rest will depend on luck, bravado and the expert advice of John Chambers and Lester Siegel, Hollywood stalwarts who give the film its Groucho Marx element.

Affleck's earlier films as a director - Gone Baby Gone (2007) and The Town (2010) - proved his talent for building suspense and choreographing action, and his re-creation of the storming of the US embassy puts you right on the spot with racing pulse and sweating palms. Despite the moustaches, the goggle-size glasses and the rest of the 1970s details, it's the kind of scene that never dates.

Affleck makes smooth work of juggling the film's widely diverging moods. There's the claustrophobic strain of the hostages' life in Tehran, where members of the Revolutionary Guard patrol the streets, making house-to-house calls in their relentless search for foreigners. There are the power plays unfolding in the CIA's corridors, which seem to exist in a bubble of their own, and counterpointing it all are Mendez's droll exploits in Hollywood.

All these components fuse in a narrative that rockets along at a pace effectively designed to disarm all critical faculties - although there are some shameless bits of American triumphalism. It is best, for instance, if you are not familiar with Liam Neeson's gung-ho portrayal of an ex-CIA man in the Taken

movies; Affleck can sound dismayingly like him. And I'm not surprised to learn that the Canadians are incensed that the film underplays the heroism and resourcefulness of their ambassador and his staff. It seems they, not the CIA, arranged the forging of the hostages' papers and the finer points of their getaway. The ambassador has also said, rather drily, that they had come up with a less intricate and equally workable escape plan. But the movies have always had a conflicted relationship with history. And few of them are as compelling as this one.