It certainly was about the most curious piece of crystal gazing I had ever done.  Turn the thing any way I pleased and I could see my face in it, just as in an ordinary mirror.

“What do you call it?” Armand asked, much interested.

“A triple mirror,” replied Kennedy, and again, half in English and half in French, neither of which I could follow, he explained the use of the mirror to the mechanician.

We were returning up the dock, leaving Armand with instructions to be at the club at dusk, when we met McNeill, tired and disgusted.

“What luck?” asked Kennedy.

“Nothing,” he returned.  “I had a ‘short’ shadow and a ‘long’ shadow at Wickham’s heels all day.  You know what I mean.  Instead of one man, two—­the second sleuthing in the other’s tracks.  If he escaped Number One, Number Two would take it up, and I was ready to move up into Number Two’s place.  They kept him in sight about all the time.  Not a fact.  But then, of course, we don’t know what he was doing before we took up tailing him.  Say,” he added, “I have just got word from an agency with which I correspond in New York that it is reported that a yeggman named ‘Australia Mac,’ a very daring and clever chap, has been attempting to dispose of some of the goods which we know have been stolen through one of the worst ‘fences’ in New York.”

“Is that all?” asked Craig, with the mention of Australia Mac showing the first real interest yet in anything that McNeill had done since we met him the night before.

“All so far.  I wired for more details immediately.”

“Do you know anything about this Australia Mac?”

“Not much.  No one does.  He’s a new man, it seems, to the police here.”

“Be here at eight o’clock, McNeill,” said Craig, as we left the club for Verplanck’s.  “If you can find out more about this yeggman, so much the better.”

“Have you made any progress?” asked Verplanck as we entered the estate a few minutes later.

“Yes,” returned Craig, telling only enough to whet his interest.  “There’s a clue, as I half expected, from New York, too.  But we are so far away that we’ll have to stick to my original plan.  You can trust Armand?”

“Absolutely.”

“Then we shall transfer our activity to the Yacht Club to-night,” was all that Kennedy vouchsafed.

CHAPTER VI

THE TRIPLE MIRROR

It was the regular Saturday night dance at the club, a brilliant spectacle, faces that radiated pleasure, gowns that for startling combinations of color would have shamed a Futurist, music that set the feet tapping irresistibly—­a scene which I shall pass over because it really has no part in the story.

The fascination of the ballroom was utterly lost on Craig.  “Think of all the houses only half guarded about here to-night,” he mused, as we joined Armand and McNeill on the end of the dock.  I could not help noting that that was the only idea which the gay, variegated, sparkling tango throng conveyed to him.