A flurry of rain, driven on a gust of cold wind, sent pedestrians running for shelter as Mallett turned into Mount Street. It was not a morning for loitering out of doors any longer than was necessary, but the inspector paused a moment beside a street hawker who stood, chilled and dripping, on the pavement. He threw sixpence into his tray, took a box of matches and looked into the man’s face as he did so, raising his eyebrows in enquiry.

“Du Pine went in half an hour ago,” murmured the hawker.

“Alone?”

The man nodded, and then whined: “Thank you, sir, God bless you, sir,” as someone brushed past them.

Mallett put the matches in his pocket and crossed the deserted street. The house he sought was almost immediately opposite, and an observer might have thought it strange that only when he had reached the other side and was within a yard or two of the door did he unfurl the umbrella in his hand. With what seemed unnecessary disregard for any other passers-by, he held it right in front of his face. At that moment two men emerged from the house door. They paused for an instant, looking right and left, before getting into a small two-seater car which was drawn up by the kerb. Not for the first time Mallett thanked the unknown inventor of the umbrella, who has supplied us with a mask, effective and opaque, which can be assumed in a moment, on at least nine days out of ten in an English winter, without attracting the least suspicion. Only one thing was needed to make it perfect from a detective’s point of view—an artistically contrived slit in the silk. Mrs. Mallett could never understand why her husband consistently refused to have his umbrella re-covered.

“Du Pine and—who?” the inspector asked himself, as he let down his umbrella in the hall, while the noise of the car receded down the street. “Thin, sandy, not too well dressed, toothbrush moustache—Captain Eales, I should imagine. Better make a note of the number of the car, anyway—VX 7810.”

To Mallett, making a note of a fact or name was merely to repeat it once to himself under his breath. Thereafter it was more securely recorded that if it had been copied into a dozen notebooks.

He turned to the porter. “Is Mrs. Eales in?” he asked.

The man nodded. “Oh, she’s in all right,” he said. There was something of a sneer in his voice, a knowing contempt that to Mallett as a man was intensely disagreeable; for Mallett the detective, like anything else out of the ordinary, it had its interest.

“Then take me up in the lift, please,” he said sharply.

“Very good, sir. It’s on the second floor. This way.”