As she approached her one hundredth birthday, Betty Webb was finally ready to tell in full the story of her extraordinary life, not least the years she spent as the only female codebreaker during the Second World War to work at both Bletchley Park and the Pentagon.

The true story of the copper at the heart of Line of Duty

'All the ingredients of a Le Carre novel, only it's real' - Matthew Hall, crimewriter and screenwriter (Keeping Faith)