Laura Poitras' Bafta-winning documentary follows her meetings with whistleblower Edward Snowden, as he reveals evidence of a massive campaign of illegal surveillance carried out on US citizens by the country's National Security Agency. When the story goes public, they find themselves at the centre of a media storm and facing decisions that would have a huge impact on their lives.

In June 2013, Laura Poitras and reporter Glenn Greenwald flew to Hong Kong for the first of many meetings with Edward Snowden. She brought her camera with her.