The story behind Rosewater is something akin to Ourobos, the ancient symbol of the snake that eats its own tail.

Written and directed by Jon Stewart, this film comes from the book Then They Came For Me: a family's story of love, captivity and survival by Iranian journalist Maziar Bahari based on his real-life story of being imprisoned and tortured by the Iranian authority for 118 days.

The story eats itself when you understand that a sketch Bahari took part in with Stewart's The Daily Show – an American political comedy show on the US cable network The Comedy Channel, in which Daily Show correspondent Jason Jones joked that he was an American spy as he was asking Bahari questions about the Iranian presidential elections – was interpreted literally by the Iranian authority, and used as evidence that Bahari was spying for the Americans.

There's a sense of frustration and guilt and fury behind Stewart's motivation and his writing and direction demonstrate this, though with restraint, and with a sense of balance to the story.

Gael Garcia Bernal plays Bahari, a London-based Iranian who returns home to cover the 2009 presidential elections for Newsweek Magazine. With his pregnant wife (Claire Foy) back home, he stays with his mother (Shohreh Aghdashloo) and heads out to cover the mood of the people on the street accompanied by his driver and guide Davood (Dimitri Leonidas).

When Ahmadinejad wins power and Bahari shares footage he has shot of protest rallies and riots with the international media, he is arrested, and thus begins a long relationship with his interrogator (Kim Bodnia) who is being leaned on heavily to win a confession from their high-profile prisoner.

Stewart gives the audience a good sense of place. He shot the film in Amman but he incorporates camcorder footage of the streets of Iran that add a great sense of colour. It is quite a way into the film before Bahari is arrested, during which time and through Bahari's interviews and wanderings do we get a sense of life in Iran at the time.

Then the plot turns and the film's second half is a two-hander between Bernal and Danish actor Kim Bodnia, both terrific, with Stewart injecting occasional humour. He isn't quite as successful with his long scenes of Bahari in solitary confinement – or perhaps he is too successful and what I felt was a lack of pace and movement was meant exactly that way to convey the long frustrating times of inertia.

Jon Stewart doesn't go the obvious and self-referential route, which would be to play on his ties to the story and insert himself into it, and this is to be commended, but it is certainly the selling-point around the film to me.