Thrill-seeker Christine Granville offers to ski across enemy lines and over the deadly Carpathian mountains, into Nazi-occupied Poland to gather intelligence for the British. Churchill would later call her his favourite spy.

Helena Bonham Carter shines a light on extraordinary stories from World War Two. Join her for incredible tales of deception, acts of resistance and courage.

A BBC Studios Audio production for BBC Radio 4 and BBC Sounds.

Producer: Suniti Somaiya Edit Producer: Melvin Rickarby Assistant Producer: Lorna Reader Executive Producer: Paul Smith Written by Alex von Tunzelmann Commissioning editor for Radio 4: Rhian Roberts