I thank the Librarian and staff of the Wiener Library in London for their help over several years.

I also wish to thank David Rosenthal and — especially — Robyn Sisman, without whom this book would never have been started, let alone finished.

Thick cloud had pressed down on Berlin all night, and now it was lingering into what passed for the morning. On the city’s western outskirts, plumes of rain drifted across the surface of Lake Havel, like smoke.

Sky and water merged into a sheet of grey, broken only by the dark line of the opposite bank. Nothing stirred there. No lights showed.

Xavier March, homicide investigator with the Berlin Kriminalpolizei — the Kripo — climbed out of his Volkswagen and tilted his face to the rain. He was a connoisseur of this particular rain. He knew the taste of it, the smell of it. It was Baltic rain, from the north, cold and sea-scented, tangy with salt. For an instant he was back twenty years, in the conning tower of a U-boat, slipping out of Wilhelmshaven, lights doused, into the darkness.

He looked at his watch. It was just after seven in the morning.

Drawn up on the roadside before him were three other cars. The occupants of two were asleep in the drivers” seats. The third was a patrol car of the Ordnungspolizei — the Orpo, as every German called them. It was empty. Through its open window, sharp in the damp air, came the crackle of static, punctuated by jabbering bursts of speech. The revolving light on its roof lit up the forest beside the road: blue-black, blue-black, blue-black.

March looked around for the Orpo patrolmen, and saw them sheltering by the lake under a dripping birch tree. Something gleamed pale in the mud at their feet. On a nearby log sat a young man in a black tracksuit, SS insignia on his breast pocket. He was hunched forward, elbows resting on his knees, hands pressed against the sides of his head — the image of misery.

March took a last draw on his cigarette and flicked it away. It fizzed and died on the wet road.

As he approached, one of the policemen raised his arm.

“Heil Hitler!”

March ignored him and slithered down the muddy bank to inspect the corpse.

It was an old man’s body — cold, fat, hairless and shockingly white. From a distance, it could have been an alabaster statue dumped in the mud. Smeared with dirt, the corpse sprawled on its back half out of the water, arms flung wide, head tilted back. One eye was screwed shut, the other squinted balefully at the filthy sky.

Tour name, Unterwachtmeister?” March had a soft voice. Without taking his eyes off the body, he addressed the Orpo man who had saluted.

“Ratka, Herr Sturmbannfuhrer.”

Sturmbannfuhrer was an SS title, equivalent in Wehrmacht rank to major, and Ratka — dog-tired and skin-soaked though he was -seemed eager to show respect. March knew his type without even looking round: three applications to transfer to the Kripo, all turned down; a dutiful wife who had produced a football team of children for the Fuhrer; an income of 200 Reichsmarks a month. A life lived in hope.

“Well, Ratka,’said March, in that soft voice again. “What time was he discovered?”

“Just over an hour ago, sir. We were at the end of our shift, patrolling in Nikolassee. We took the call. Priority One. We were here in five minutes.”

“Who found him?”

Ratka jerked his thumb over his shoulder.

The young man in the tracksuit rose to his feet. He could not have been more than eighteen. His hair was cropped so close the pink scalp showed through the dusting of light brown hair. March noticed how he avoided looking at the body.

“Your name?”

“SS-Schutze Hermann Jost, sir.” He spoke with a Saxon accent — nervous, uncertain, anxious to please. “From the Sepp Dietrich training academy at Schlachtensee.” March knew it: a monstrosity of concrete and asphalt built in the 1950s, just south of the Havel. “I run here most mornings. It was still dark. At first, I thought it was a swan,” he added, helplessly.

Ratka snorted, contempt on his face. An SS cadet scared of one dead old man! No wonder the war in the Urals was dragging on forever.

“Did you see anyone else, Jost?” March spoke in a kindly tone, like an uncle.

“Nobody, sir. There’s a telephone box in the picnic area, half a kilometre back. I called, then came here and waited until the police arrived. There wasn’t a soul on the road.”

March looked again at the body. It was very fat. Maybe 110 kilos.

“Let’s get him out of the water.” He turned towards the road. Time to raise our sleeping beauties.” Ratka, shifting from foot to foot in the downpour, grinned.

It was raining harder now, and the Kladow side of the lake had virtually disappeared. Water pattered on the leaves of the trees and drummed on the car roofs. There was a heavy rain-smell of corruption: rich earth and rotting vegetation. March’s hair was plastered to his scalp, water trickled down the back of his neck. He did not notice. For March, every case, however routine, held — at the start, at least — the promise of adventure.

He was forty-two years old — slim, with grey hair and cool grey eyes that matched the sky. During the war, the Propaganda Ministry had invented a nickname for the men of the U-boats — the “grey wolves” — and it would have been a good name for March, in one sense, for he was a determined detective. But he was not by nature a wolf, did not run with the pack, was more reliant on brain than muscle, so his colleagues called him “the fox” instead.

U-boat weather!

He flung open the door of the white Skoda, and was hit by a gust of hot, stale air from the car heater.

“Morning, Spiedel!” He shook the police photographer’s bony shoulder. Time to get wet.” Spiedel jerked awake. He gave March a glare.

The driver’s window of the other Skoda was already being wound down as March approached it. “All right, March. All right.” It was SS-Surgeon August Eisler, a Kripo pathologist, his voice a squeak of affronted dignity. “Save your barrack-room humour for those who appreciate it.”