The spy catchers close in. Klaus Fuchs is caught in the crosshairs. Spymaster Ursula has outwitted the interrogators - but can he? As he settles down in England, British intelligence services are following him at every turn. He is caught in a web of surveillance - and his faith in the Soviets is faltering. How long can he run for? #thebomb

https://www.bbc.co.uk/programmes/p0cq4bs7