It’s London, 2012. Oliver is a dashing diplomat. Charlie is a young graduate trying to find her feet in the world. They meet online and she falls in love. A few months into the relationship, and with his encouragement, Charlie applies for a job in British intelligence. She’s feeling optimistic, the interview goes well. Then, she receives a text message that turns her life – and her relationship – upside down. 10 years later, a mystery is still hanging over her. Walter’s War is an investigation into what happened next – a journey through big tech and national security, hype and hucksterism, where anyone who can tell a good story can go far. But how much is true?