Walking briskly from the street into the Shelbourne Hotel in London’s West End, a beautiful, smartly dressed guest had started to climb the stairs when a man hurried into the foyer behind her and called out to her.

She stopped, turned, and came down the few stairs to speak to him. It was 10.15 p.m. on JUNE 15th, 1952, and the night porter looked round in surprise as he heard a commotion and saw the pair struggling. “Get him off me!” the guest screamed.

As the porter and two colleagues rushed to help her, a knife flashed in the man’s hand and the woman collapsed, the dagger up to its hilt in her chest. Grabbed by the witnesses, the man offered no resistance. “I loved her,” he said, looking down at his victim’s crumpled body. “I killed her. Let’s get away from her and get it over with.”

He was Dennis George Muldowney, a porter at London’s Reform Club and formerly a ship’s steward. The murdered woman was Christine Granville, a regular guest at the Shelbourne ever since World War II, and something of a mystery. The manager said he was puzzled that such a quiet, gracious and cultured woman seemed to take jobs far beneath her – her most recent employment was as a ship’s stewardess. It was if she had been trying to hide, or to escape from, some secret of her past.

The mystery deepened when detectives searched her room and found the French Croix de Guerre, the Order of the British Empire and the George Medal for valour. How had a ship’s stewardess come to receive such awards?

Then the detectives were visited by representatives of MI5 and Scotland Yard’s Special Branch intelligence service, who asked to be kept informed of the investigation’s progress. They said that Christine Granville had been a British agent, but offered no further information.

The detective chief inspector leading the inquiry was baffled. Was Muldowney a foreign agent, and Christine Granville the victim of some international intrigue?

The investigation, however, uncovered nothing more than a simple but tragic solution to the mystery. Muldowney and his victim had been colleagues on ocean-going liners. Christine had befriended Muldowney, a lonely nobody, and in falling in love with her he had mistaken her kindness for something else. But she had other, far more distinguished lovers – Ian Fleming, James Bond’s creator, reportedly among them.

On finding that his feelings were not reciprocated, Muldowney had become embittered and in his anguish he had killed her. Pleading “Guilty” at his Old Bailey trial for murder, he was hanged at Pentonville Prison on September 30th, 1952.

Meanwhile the police had learned Christine Granville’s real identity. She was Countess Krystyna Skarbeck. Parachuting into France and Hungary and establishing sabotage groups in Poland, she had become a heroine of the Resistance, her exploits legendary. Throughout the war she had risked her life daily…only to be slain in a London hotel by a disgruntled would-be lover.