Rosemarie lay on her back, sprawled out over the thick Persian carpet. She was still wearing a smart, low-cut evening dress, pulled up over her thighs to reveal her nylon-stockinged legs and suspenders.

Her left foot was under the sofa, her right foot was under a cushion on the sofa. Her platinum blonde hair was dishevelled, her sightless eyes were swollen in their sockets, and her scarlet lips were twisted in an ugly grimace.

There were bruises and discoloration plain to see on her open throat, caused by her killer’s fingers squeezing the last gasp of life out of her.

The Princess of Vice, as they called her, had received her last paying customer, and beyond any doubt he was an ugly one. She had been strangled, and there was a three-centimetre wound in the back of her head.

Detectives studying the apartment for clues were struck by the sheer luxury of it. The dead woman was only 25, and this was a West Germany still recovering from the ravages of war.

Yet here in the middle of streets only recently cleared of bomb rubble were costly furnishings for which someone must have paid a small fortune – beautiful carpets, tapestries, and an astonishing number of mirrors…