From James Bond to Jason Bourne, the fictional world of spying is a world of danger and deception, glamour and lies. But how does the myth compare with the reality?
In the first of two programmes, Peter Taylor looks at the real world of modern spies. For the first time on television, serving British secret agents talk about their work - from an MI6 agent runner to an MI5 surveillance officer.
This time, Modern Spies investigates how today's spies are recruited and probes the secrets of spycraft, from the sleeper cell to the brush pass and the cut out to the cyber spy.