The tools in a spy's arsenal are more varied than you might think. But they all come under one name: Tradecraft.

In our tenth round of insights from the world of espionage, Rhiannon Neads looks back on gadget masters, Cold War tunnel-digging and the art of the Mobile Debrief.

From SPYSCAPE, the HQ of secrets. A Cup And Nuzzle production. Series producer: Joe Foley. Produced by Alex Burnard. Music by Nick Ryan.

Learn more about your ad choices. Visit megaphone.fm/adchoices