There was a searchlight near by on the dock.
"You can use that?" queried Kennedy.
"Oh, yes. Mr. Verplanck, he is vice-commodore of the club. Oh, yes, I can use that. Why, Monsieur?"
Kennedy had uncovered a round brass case. It did not seem to amount to much, as compared to some of the complicated apparatus he had used. In it was a four-sided prism of glass--I should have said, cut off the corner of a huge glass cube.
He handed it to us.
"Look in it," he said.
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.
In front of the club was strung out a long line of cars, and at the dock several speed boats of national and international reputation, among them the famous Streamline II, at our instant beck and call. In it Craig had already placed some rather bulky pieces of apparatus, as well as a brass case containing a second triple mirror like that which he had left with Armand.
With McNeill, I walked back along the pier, leaving Kennedy with Armand, until we came to the wide porch, where we joined the wallflowers and the rocking-chair fleet. Mrs. Verplanck, I observed, was a beautiful dancer. I picked her out in the throng immediately, dancing with Carter.
McNeill tugged at my sleeve. Without a word I saw what he meant me to see. Verplanck and Mrs. Hollingsworth were dancing together. Just then, across the porch I caught sight of Kennedy at one of the wide windows. He was trying to attract Verplanck's attention, and as he did so I worked my way through the throng of chatting couples leaving the floor until I reached him. Verplanck, oblivious, finished the dance; then, seeming to recollect that he had something to attend to, caught sight of us, and ran off during the intermission from the gay crowd to which he resigned Mrs. Hollingsworth.
"What is it?" he asked.
"There's that light down the bay," whispered Kennedy.
Instantly Verplanck forgot about the dance.
"Where?" he asked.
"In the same place."
I had not noticed, but Mrs. Verplanck, woman-like, had been able to watch several things at once. She had seen us and had joined us.
"Would you like to run down there in the Streamline?" he asked. "It will only take a few minutes."
"Very much."
"What is it--that light again?" she asked, as she joined us in walking down the dock.
"Yes," answered her husband, pausing to look for a moment at the stuff Kennedy had left with Armand. Mrs. Verplanck leaned over the Streamline, turned as she saw me, and said: "I wish I could go with you. But evening dress is not the thing for a shivery night in a speed boat. I think I know as much about it as Mr. Verplanck. Are you going to leave Armand?"
"Yes," replied Kennedy, taking his place beside Verplanck, who was seated at the steering wheel. "Walter and McNeill, if you two will sit back there, we're ready. All right."
Armand had cast us off and Mrs. Verplanck waved from the end of the float as the Streamline quickly shot out into the night, a buzzing, throbbing shape of mahogany and brass, with her exhausts sticking out like funnels and booming like a pipe organ. It took her only seconds to eat into the miles.
"A little more to port," said Kennedy, as Verplanck swung her around.
Just then the steady droning of the engine seemed a bit less rhythmical. Verplanck throttled her down, but it had no effect. He shut her off. Something was wrong. As he crawled out into the space forward of us where the engine was, it seemed as if the Streamline had broken down suddenly and completely.
Here we were floundering around in the middle of the bay.
"Chuck-chuck-chuck," came in quick staccato out of the night. It was Montgomery Carter, alone, on his way across the bay from the club, in his own boat.
"Hello--Carter," called Verplanck.
"Hello, Verplanck. What's the matter?"
"Don't know. Engine trouble of some kind. Can you give us a line?"
"I've got to go down to the house," he said, ranging up near us. "Then I can take you back. Perhaps I'd better get you out of the way of any other boats first. You don't mind going over and then back?"
Verplanck looked at Craig. "On the contrary," muttered Craig, as he made fast the welcome line.
The Carter dock was some three miles from the club on the other side of the bay. As we came up to it, Carter shut off his engine, bent over it a moment, made fast, and left us with a hurried, "Wait here."
Suddenly, overhead, we heard a peculiar whirring noise that seemed to vibrate through the air. Something huge,