City of Ghosts review: Life and death in Syria's Raqaa

Matthew Heineman has moved on from Cartel Land, his gripping study of Mexican drug wars, to an examination of the citizen journalists bravely standing up to Islamic State in the Syrian city of Raqqa. The award-winning movement known as Raqqa is Being Slaughtered Silently (RBSS) have worked hard to counteract the stream of propaganda coming from the self-proclaimed caliphate. Their reward has been persecution and exile. Their role has evolved as the tyranny grew. They began by documenting the arrival of Islamic State forces and then moved on to reporting the vicious retaliation against any counter-insurgency. Bodies are suspended in busy shopping streets. Dissenters are executed in public. Their own footage offers evidence of the reporters' bravery.

City of Ghosts stands as a worthwhile tribute to remarkable people. But it has little of the propulsive power of Cartel Land. Heineman does not begin his story until the men have left Syria for Turkey and, as a result, much information is related second-hand. Some tension is injected into proceedings as – now working from safe houses in Germany – they learn that they are under constant danger. But too much of the film is taken up with anxious chatter.

The film is at its best (and its most terrifying) when relaying the footage from RBSS. Heineman has to tread a difficult line here. He needs to convey the horror, but too many shots of too many appalling slaughters would risk turning his documentary into a snuff movie. He gets the balance about right. There is a chilling sense of the unspeakably horrible playing out amid the everyday business of ordinary citizens.

City of Ghosts sticks close to its subjects and hears some terrible news. At least one senior figure is killed in the progress of the film. As they are sheltering in Germany, they rub up against a neo-Nazi protest. Fear is everywhere.

There are the makings of a gripping story in these elements. But somehow City of Ghosts never quite comes together. It feels as if the correct subject had been approached from the wrong angle. Still, the picture should send a few viewers in search of the subjects' admirable work.