For the past year, our operative Patrik Hermansson has been living undercover, as Swedish student Erik Hellberg, at the heart of the alt-right. He infiltrated some of the most notorious far-right networks in the US and the UK, culminating in the violent clashes in Charlottesville 2017. He extracted damning information that runs all of the way to the White House. And he caught it all on hidden camera.

• Documentary