The Hollingsworth house was a beautiful little place down the bay from the Yacht Club, but not as far as Verplanck’s, or the Carter estate, which was opposite.

“Yes,” replied Mrs. Hollingsworth when the reason for our visit had been explained, “the attempt was a failure. I happened to be awake, rather late, or perhaps you would call it early. I thought I heard a noise as if some one was trying to break into the drawing-room through the window. I switched on all the lights. I have them arranged so for just that purpose of scaring off intruders. Then, as I looked out of my window on the second floor, I fancied I could see a dark figure slink into the shadow of the shrubbery at the side of the house. Then there was a whirr. It might have been an automobile, although it sounded differently from that—more like a motor boat. At any rate, there was no trace of a car that we could discover in the morning. The road had been oiled, too, and a car would have left marks. And yet some one was here. There were marks on the drawing-room window just where I heard the sounds.”

Who could it be? I asked myself as we left. I knew that the great army of chauffeurs was infested with thieves, thugs and gunmen. Then, too, there were maids, always useful as scouts for these corsairs who prey on the rich. Yet so adroitly had everything been done in these cases that not a clue seemed to have been left behind by which to trace the thief.

We returned to Verplanck’s in the Streamline in record time, dined, and then found McNeill, a local detective, waiting to add his quota of information. McNeill was of the square-toed, double-chinned, bull-necked variety, just the man to take along if there was any fighting. He had, however, very little to add to the solution of the mystery, apparently believing in the chauffeur-and-maid theory.

It was too late to do anything more that night, and we sat on the Verplanck porch, overlooking the beautiful harbor. It was a black, inky night, with no moon, one of those nights when the myriad lights on the boats were mere points in the darkness. As we looked out over the water, considering the case which as yet we had hardly started on, Kennedy seemed engrossed in the study in black.

“I thought I saw a moving light for an instant across the bay, above the boats, and as though it were in the darkness of the hills on the other side. Is there a road over there, above the Carter house?” he asked suddenly.

“There is a road part of the way on the crest of the hill,” replied Mrs. Verplanck. “You can see a car on it, now and then, through the trees, like a moving light.”

“Over there, I mean,” reiterated Kennedy, indicating the light as it flashed now faintly, then disappeared, to reappear further along, like a gigantic firefly in the night.

“N-no,” said Verplanck. “I don’t think the road runs down as far as that. It is further up the bay.”

“What is it then?” asked Kennedy, half to himself. “It seems to be traveling rapidly. Now it must be about opposite the Carter house. There—it has gone.”