Ellery Queen’s Mystery Magazine. Vol. 26, No. 4. Whole No. 143, October 1955

“It’s crazy, I know, and we shall probably find the diamond in the safe just where Daddy put it. But look, Professor Fen: Uncle Harry’s meeting me at the house tomorrow morning to unlock the study and — and to go through its contents. He’s been in America up to two days ago, so there hasn’t been a chance before. If I could just have someone with me...”

Gervase Fen nodded. “I’ll come,” he said. For he had known Ann Cargill long enough to be aware that, however erratic her views on Beowulf or Dryden, she was nobody’s fool.

Uncle Harry proved to be a big, florid, amiable man dressed in checks with a black arm-band. And like his niece, he appeared at the Abingdon house next morning with a companion.

“Humbleby!” said Fen, pleased.

“Well, well,” Said Inspector Humbleby of Scotland Yard as he shook Fen’s hand. “And what are you doing here?”

“Looking for a diamond,” said Fen. “Miss Cargill is a pupil of mine. Ann, meet the Inspector.”

“We’re all looking for a diamond,” said Uncle Harry. “And from what the Inspector told me yesterday, there’s a damn good chance we shan’t find one.”

“Twenty thousand pounds,” said Humbleby, “is about what the average high-class fence would give for a diamond like your father’s, Miss Cargill. And twenty thousand pounds is exactly what Mr. Spottiswoode’s executors found hidden in his house after his death. Being honest men, they came and had a word with us about it at the Yard. We’ve been working on the case for a fortnight now, and we still don’t know where that money came from. Nothing legitimate, you can be sure...

“But there was never any secret about your father’s buying that jewel; and his death was reported in the papers; and his name was on the list of Mr. Spottiswoode’s clients. So of course we started putting two and two together, and yesterday I had a word with your Uncle about it, and he very kindly invited me down here, subject to your having no objection—”

“Of course not,” said Ann.

“So that now,” Humbleby concluded, “we shall see what we shall see.”

A woman, Ann explained, had been coming in once or twice a week to keep the house dusted, but her ministrations had not, of course, included the study, which would undoubtedly be in a mess. And so it turned out. When Uncle Harry had manipulated the elaborate locks, thrown the study door open and switched on the lights (for the room was in darkness, thanks to the solid steel shutters on the windows), they saw that dust — five weeks’ dust — lay undisturbed on the furniture, the bare polished boards of the floor — over everything.

Also it was cold in there. While Uncle Harry fumbled with the safe, Ann turned on the big electric fire and stood warming her hands in front of it. Presently Fen, who had been peering at the marks left by their feet on the dusty floor, lifted his head and sniffed.

“Is there something burning?”

They all sniffed.

“I can’t smell anything,” said Ann.

“Nor me,” said Humbleby.

“Nor me,” said Uncle Harry, pausing in his labors; and added ruefully: “But then, it’s years since I was able to smell anything.”

Fen shrugged. “My mistake,” he said; though as a matter of feet it had not been a mistake, since he himself had not been able to smell anything burning, either. His eye caught Humbleby’s. “Dog,” he confided solemnly, “in the night-time.”

Humbleby scowled. “Dog in the—”

“Eureka!” said Uncle Harry inaccurately; actually, all he had contrived to do was to get the safe door open. But a moment later he emerged from it holding a handsome jewel box. “Would this be—”

“Yes, that’s it,” said Ann. “Open it, please.”

And Uncle Harry opened it.

It was empty.

“It couldn’t,” Humbleby suggested, “be somewhere else?”

“No.” Ann shook her head decisively. “I was with my father just before he left, and that was where he put it.”

Uncle Harry grunted. “Anyway, there’s your explanation of Spottiswoode’s twenty thousand.”

But Fen apparently did not agree. “No,” he said. “Insufflator.”

“Beg pardon?”

“Insufflator. For example, one of those rubber-bulb things barbers use for blowing powder onto your chin. And dust, as such, isn’t really very hard to come by. It would take a little time, and a little care, but I’m willing to bet that given twenty-four hours you could redust this entire room.”

An ugly gleam had appeared in Uncle Harry’s eye. “Just what,” he enunciated slowly, “are you suggesting?”

“I was suggesting a likely means for you to have used to cover up your traces after stealing the diamond. You stole it last night, I suppose, after Humbleby’s account of Spottiswoode’s hoard — which I should guess is probably blackmail money accumulated over a good many years — had suggested to you how you could disperse the blame. As to why Spottiswoode didn’t forestall you — well, it may simply be that he didn’t know of any means of disposing of such a distinctive stone.”