“I don’t know,” said Mr Rochborne darkly. “Maybe nothing. Maybe something. But one thing I do know, I’m going to be there when this ‘Professor’ ” — he put quotation marks around the title — “holds his ‘demonstration’ tomorrow morning. It’s probably a lot of horseshoes, but we can’t afford to take any chances.”

Simon Templar might have hoped for a more impressive turnout in response to his carefully planted publicity, but he could also have been guilty of discounting Larry Phelan’s estimate of the skepticism of local wiseacres in the matter of Doodlebugs. The Lucky Nugget mine site on Thursday morning was fairly uncrowded by seven male and two female citizens of the nearby town of Clementine Valley, all more or less the worse for wear; four small boys; three cynical reporters, two dogs, and a passing hobo attracted by the crowd. But to Simon Templar the most important spectator was a large well-built man, conspicuous in city clothes, with a kindly face, to whom the dogs and small boys aforesaid were immediately attracted, and whose eyes missed no detail of the proceedings in the intervals of ministering to posterity and its pets.

The Saint had arrayed himself for the occasion in what seemed a likely professorial costume of Norfolk jacket, pith helmet, and riding boots, with the addition of a gray goatee which sat rather strangely on his youthful brown face.

He eyed the gathering individually and collectively with an equal interest as he stepped from Clementine Valley’s only taxicab, tenderly bearing the wooden box, replete with knobs and dials, which was obviously the one and only Tattersall Magnetic Prospector.

“Good morning, gentlemen,” he said.

“Hey, Prof,” queried a high thin voice from the group, “will she bring in London?”

This sally elicited a wave of home-town laughter, to which Simon professorially paid no heed. He reconnoitred situation and terrain with the bold eye and flaring nostril of an intrepid conquistador.

When one spoke of the Lucky Nugget mine, one meant nine hundred and twenty-eight feet of partially caved-in tunnel sunk into the bowels of a red-dirt pine-freckled hill. The tunnel entrance was half blocked by fallen dirt and broken timbers. From it emerged two streaks of rust which had once been rails for ore cars to run on, and which descended a gentle slope to the remains of a stamp mill.

Professor Simeon Tattersall sapiently eyed the tunnel mouth, grasped his device, and took a step toward the opening. “Mind if I look at your gadget, Professor?” said a genial voice.

Simon looked around, and found the man in the city clothes standing at his elbow.