Julius Boden stroked Lilly’s hair. She was nestling into his arms in the back of the car, holding him as though she would never let him go. He kissed her again, then whispered words of love in French into her ear.

Ahead of them, snow swirled in mysterious patterns in the headlights of the Mercedes.

Not for the first time, he thought back to the time he met Lilly Marais in the summer of 1943. He had been in the back of a Mercedes like this one, driving from the Normandy coast to Rouen. It had been a long day. He had been inspecting improvements to his sector of the vast system of fortifications known as the Atlantic Wall and he had not been happy with what he had seen. There were still gaps – blind spots on the shoreline that the machine-gunners could not cover. Such oversights mattered; one had to be prepared for all eventualities – even the unlikely arrival of an enemy landing force.

Bored, reluctant officers and engineers had had to be cajoled and threatened with unpleasant deployments elsewhere if they didn’t rectify the problems in short order. Of course, they all recognised him and watched him as though he were a film star. His fame had travelled far and wide in the Reich. The upshot of that was that there were those who didn’t take him seriously as a soldier. Good for a picture in the papers, nothing more. Well, they’d soon learn the truth when he sent them east to face a bombardment by the Ivans.

Though weary from his day’s work, he had been happy and in a good mood as they drove through the village of Ste Estelle-sur-Seine. It wasn’t a particularly memorable place. Just another northern French farming community and, anyway, his mind was elsewhere – the prospect of a few drinks and a bit of dancing at the midsummer ball.

But then, out of the corner of his eye, he saw her.

Standartenführer Boden had enjoyed the company of many beautiful women in his young life, including the finest beauties of Berlin and Munich. But Lilly was different. This was like chancing upon a Michelangelo sculpture or a Mozart symphony for the first time.

She was with a group of four other girls, running down the street, laughing, until suddenly they saw the open-topped staff car with its swastika flags and came to a sudden halt as if struck by a bullet. They stood rigid at the side of the road and waited for it to pass.

But Boden spoke in the driver’s ear, telling him to stop. Slowly, the car backed up until the vehicle was alongside the five girls. Boden summoned them to him with a curl of his gloved fingers.

The girls were all in summer dresses. Scraps of bright material that swayed in the light June breeze and showed off their tanned legs and arms. Their hair was loose and long.