“That’s the word. The pundit from the Museum says it came from Borneo. They don’t know what the marks mean, but the thing is a sort of mascot in Borneo: a high-class insurance policy. The fellow who holds it can’t die. So the simple Bornese don’t part with their pebbles easily. There isn’t another known in Europe. That’s where it hurts the Museum pundit. He says it’s priceless. I told him marbles were selling thirty a penny. Nice round marbles, all colours.”

“Yes. You have no soul, Lomas.”

“I dare say. I’m busy.”

“With toxic spouses!” said Reggie reproachfully. “Green, was it? Green quartz, I suppose, or perhaps jade with the pattern in oxide of iron.”

“And I expect some child has swopped it for a green apple.”

“Lomas dear,” Mr. Fortune expostulated, “this is romance. Ten thousand years ago the cave men in France painted these patterns on stones. And still in Borneo there’s men making them for magic. Big magic. A charm against death. And some bright lad comes down to Bloomsbury and throws a fit to steal one. My hat, he’s the heir of all the ages! I could bear to meet this epilept.”

“I couldn’t,” said Lomas. “I have to meet quite enough of the weak-minded officially.”

But Reggie Fortune was deaf to satire. “A magic stone,” he murmured happily.

“Oh, take the case by all means,” said Lomas. “I’m glad I’ve brought you something that really interests you. Let me know when you find the pebble,” and announcing that he had a day’s work to do on the morrow, he went with an air of injury to bed.

It was an enemy (a K.C. after a long and vain cross-examination) who said that Mr. Fortune has a larger mass of useless knowledge than any man in England. Mr. Fortune has been heard to explain his eminence in the application of science to crime by explaining that he knows nothing thoroughly but a little of everything, thus preserving an open mind. This may account for his instant conviction that there was something for him in the matter of the magic stone. Or will you prefer to believe with Superintendent Bell that he has some singular faculty for feeling other men’s minds at work, a sort of sixth sense? This is mystical, and no one is less of a mystic than Reggie Fortune.