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 feels optimistic, the interview goes well but 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?

Basia begins unravelling the ‘tissue of lies', but it becomes clear that some of Oliver's claims exist in the grey area, and in the secretive world in which he works, it's hard to sift fact from fiction. Did he serve in the military? Is he an aristocrat? And as she traces his rise in national security, she is pulled into a bigger story – about a company, and a threat that is facing us all.

Basia begins unravelling the ‘tissue of lies', but it becomes clear that some of Oliver's claims exist in the grey area, and in the secretive world in which he works, it's hard to sift fact from fiction. Did he serve in the military? Is he an aristocrat? And as she traces his rise in national security, she is pulled into a bigger story – about a company, and a threat that is facing us all.