Oscar-nominated documentarian Matthew Heineman follows up Cartel Land (his brutal expose of Mexico’s drug wars) with a film that is both truly shocking and moving. City of Ghosts tells the story of a group of citizen journalists risking their lives to show the world the harsh realities of life under Isis rule on the battered streets of Raqqa (Islamic State’s self-proclaimed capital), at the heart of the Syrian conflict.

As a collective, they are known as Raqqa is Being Slaughtered Silently (RBSS) and won the International Press Freedom Award in 2015 for their groundbreaking work as one of Syria’s few independent news sources. To share their videos of brutal beheadings and executions -in the now ironically named Freedom square – and the chilling aftermath of US-led airstrikes (which UN investigators confirm have caused a staggering loss of civilian life) RBSS rely on the bravery of their members trapped in Raqqa to deliver the truth via satellite linked smartphones.

Heineman spends time with the group’s exiled members at (relatively) safe houses in Germany and in Gaziantep, on the Turkish border with Syria, where they upload the videos and breaking news they receive to the RBSS website and update the world with the latest stories from the region via social media.

We meet Hamoud who confesses that “danger has a special taste”. It’s a remark that might seem charged with bravado but this is a man committed to showing the truth at the cost of his own personal safety. “Whoever holds the camera is stronger,” he says. The group’s spokesman Aziz reveals “the revolution changed us” and we soon learn this band of brothers and sisters have all lost loved ones and had their lives torn apart. Because their work comes at a heavy cost.

In one heart-wrenching scene we watch as Hamoud replays a video of his father’s execution. As the camera turns away our natural impulse is to hope he never has to watch it again, but he reveals a dark truth: “It makes me stronger…” For their fight will continue. It must. To watch this film is to have your eyes forced open. To be wrenched from your comfort zone and appreciate the human stories behind the headlines. Heineman says, “It’s my job to provide a human face to this and allow the audience to go on an emotional journey. Hopefully, because of that, they’ll have a bit more empathy for this group, the people of Raqqa, the people of Syria and immigrants across the world who are being forced to flee their homes.”

His compelling portrait reveals a group of friends old beyond their years. Yearning for their homeland and the chance to rebuild not only their lives but the lives of their compatriots, they are shining a light in the darkness, a beacon of hope for the future. City of Ghosts makes for humbling and essential viewing.

City of Ghosts is released on July 21st.