“This would be one of the worst films ever made if it wasn’t a true story,” Ben Affleck admits in a press interview for Argo, and he’s right.

This pottiest of pot boilers sees six US Embassy staff escape into Tehran when a crowd breaches their secure complex and takes everyone else hostage. Fearing for their lives if they are caught by the Iranian hardliners, their possible escape routes sit squarely between a rock and a hard place.

That’s until CIA exfiltration expert Tony Mendez (Ben Affleck) comes up with a crazy plan to shoot a made-up sci-fi film in Iran, sneaking the six out as Canadian filmmakers once they’ve scouted possible locations. Cue the creation of a fake studio, the interest of a known director and the search for a suitable script. The premise is bonkers – but given that it is true, also fascinating.

Affleck doubles up on directing duty and manages to pull off a difficult task in that area. Mixing the very real fear of execution with some genuine humour and sly digs at the LA film industry is a difficult juggling act, but for the most part it hangs together. He gives Argo the pace and attitude of a heist movie, the weird vibe of Star Wars and even occasionally throws in the swagger of Anchorman as part of his ’70s setting. Some of the taches are so luscious it’s a wonder part of the ticket price isn’t being handed over to charity for Movember.

His cast also do him proud. Victor Garber, Tate Donovan, Clea DuVall, Scoot McNairy, Rory Cochrane and Christoper Denham excel as the bickering Embassy staff unsure of whether to trust Mendez or not. Meanwhile, John Goodman (glib as hell as real-life make-up artist John Chambers) and Alan Arkin (on his best grumpy form) handle the Hollywood (or should that be ‘LLYWO D’ as the sign read in those days) side of things with aplomb. Bryan Cranston also continues an excellent run as Mendez’s boss, proving it’s almost impossible to pigeonhole him.

In fact, the only real weak link is Affleck himself. Directing, producing and starring is a tough gig and perhaps it took its toll, as it’s his character that rises least to the challenges facing all those involved. Waking up in what looks like Tracey Emin’s bed and chatting to his 10-year-old son on the phone feel like lazy attempts to fill out Mendez’s backstory. And while, admittedly, he’s supposed to be the cool and professional one of the group, we never really get the sense that he feels the danger or the pressure of the situation – despite the inclusion of the inevitable fuck-you scene as he argues with his superiors.

As for Affleck’s quote, about Argo being one of the worst films ever made had it not been true? It easily avoids that thanks to its effective period recreations, fine character acting, some truly gripping moments and a plot that really does defy belief.

VERDICT: 8/10

Argo was released in US cinemas on 12 October 2012 and is in UK cinemas 7 November 2012.