Krystyna Skarbekthe ForgeESTP

In August 1944, at 36, Krystyna Skarbek walked round the walls of the prison at Digne, in the south of France, humming “Frankie and Johnny”.

Inside were three comrades: Francis Cammaerts, who led her resistance network, Xan Fielding and Christian Sorensen. The Gestapo had arrested them at a roadblock on 13 August. Men taken like that, in the last days of a collapsing occupation, were expected to be shot.

From inside, Cammaerts picked up the tune. No code, no radio. Just a song two friends both liked, sent over a wall and sent back. Now she knew he was alive.

Born in Warsaw on 1 May 1908, to a Polish noble father and a mother from a Jewish banking family, she reached London on 6 October 1939 and asked to fight. British intelligence took her on, and in time she became Christine Granville. Arrested in Budapest in 1941, she bit her tongue until it bled and convinced a doctor she had tuberculosis.

When she heard, she was high in the Alps, talking Polish conscripts in a German garrison into deserting. She hurried back and, though she hated bicycles, cycled 40 kilometers to Digne.

Her first plan was force. She tried to persuade resistance leaders to storm the prison, and they would not. So she went in with a story instead.

She found Captain Albert Schenck, an Alsatian who dealt with the Gestapo for the local prefecture. She told him she was Cammaerts's wife and a niece of General Montgomery, and that when the Allies arrived, any harm to the prisoners would bring terrible reprisals. Only the last part was true, and that was a forecast.

She offered two million francs, air-dropped to her for the purpose. Schenck brought in the man who could open the cells: Max Waem, a Belgian working for the Gestapo. They met at four in the afternoon on 17 August, and for three hours she argued and bargained.

Forges read people the way sailors read weather. Waem was a frightened man with the Allies a few days away. She saw it, and offered him the thing he wanted most: a future.

That evening Waem, in his SS uniform, marched the three men out and drove them to meet her outside town. Fielding then helped him bury the tunic by a river. Two days later Digne was free.

The fear came later. Years afterward she told a fellow Pole: “What have I done! They could have shot me as well.” Fear that arrives after the danger is a very Forge thing.

She kept her promise to Waem, standing up to her own superiors to protect him. Peace was harder. After the George Medal, the OBE and the Croix de Guerre came jobs answering telephones and working on liners. On 15 June 1952, at 44, she was murdered in a London hotel by an obsessed former colleague, a crime that was his alone.

Xan Fielding dedicated his memoir of the war to her memory. Cammaerts named his daughter Christine. The men she talked out of that prison carried her name for the rest of their lives.