and presently began to hum under his breath the air Champ Ferris was laboriously coaxing from a much harassed guitar. Then, unconsciously, his glance swept past the lounging figures of his friends and out across the wide stretches of shadowy water vaguely luminous under the stars. Back of those shadows Loon Island lay, with all the other rocky little islets that crowded the entrance to Shelbourne harbor. And, perhaps, on Loon Island—

Suddenly Steve awoke to a realization of where his thoughts had carried him, and moved abruptly with an impatient squirm.

“Easy, boy, easy,” murmured Cavvy drowsily.

Grinning shame-facedly, Steve reached down and ruffled the other’s hair. A perfunctory scrimmage followed. But Cavanaugh was too drowsy to carry this far. And very shortly Mr. Wendell’s orders sent the crowd staggering sleepily tentwards.

A little later, crawling into his blankets, Steve reached a sudden, abrupt decision. Since he could not seem to rid his mind of the problem which had been raised there, why not make an effort to solve it? Very likely the answer would be a simple one not worth his trouble, but at least it would be an answer. Suppose he got another look at the perplexing stranger? If he saw him again that stubborn memory might awake.

“I’ll take a trip to Loon Island to-morrow,” he said to himself. Then he turned over and went to sleep.

CHAPTER VI
LOON ISLAND

Steve said nothing to anyone next day of his determination. He knew he would be laughed at, for he felt himself that it was a rather foolish proceeding, and it would be difficult or impossible for him to explain in words the curious intensity of his interest in the matter. So he did not even take Cavanaugh into his confidence, merely explaining that he was going for another little trip in the canoe. Cavvy’s approval was prompt, but there was just a touch of disappointment in his manner which made Steve a little troubled.

Was he making a fool of himself or not, he wondered, as he slid out into the Sound from behind the point. A portion of Loon Island was visible now and he glanced speculatively in that direction. For all he knew the stranger whose face had so puzzled him might not be in the neighborhood again for days or weeks. His presence yesterday could easily have been the result of a chance excursion never to be repeated. Nevertheless, once started, he had no thought of giving up the trip, for he was not the sort to turn aside readily from something he had once set his mind upon. So he dismissed his doubts and sent the canoe forward resolutely.

The surface of the Sound was smooth—almost too smooth, in fact. There was an oily look to the long, easy swells which rolled the canoe ever so slightly as it cut across them. Once or twice Steve glanced back and frowned a little at the smoky, golden haze hugging the eastern horizon. But he paddled steadily, keeping fairly close to shore; and when he came opposite the group of islands and headed his craft across the half-mile stretch which separated the nearest one from the mainland, the storm signals had not increased.

“I guess it’s going to hold off for a while,” he decided. “Anyhow, at the worst I’d be stuck on the island over night—which wouldn’t kill me.”

Presently he came abreast of the first little islet and passed it, passed the next one, and then turned into a narrow, rock-bordered channel along the north side of Loon Island. The tide ran swiftly here, but it carried him with it and without much effort he managed to circle the lower end of the island and reach the point where he had landed the day before. Here he stepped ashore, and pulling up the canoe, hid it in a thicket of juniper. It was still fairly early—an hour and a half earlier, in fact, than when Steve had glimpsed the man in the dory yesterday afternoon. But he had planned for this deliberately. He wanted to take a look over the island before returning to the point to watch for the stranger.

Back of the point the rocks rose steeply, with stunted pines, scrub oak and a tangle of scraggly bushes growing from every conceivable crevice and earth-pocket. It was far from easy going, but Steve pushed his way through the undergrowth with only an occasional pause, keeping as close to the shore as possible.

Presently he came upon a gully, slid into it, climbed the other side and finally, pushing through a grove of wind-tossed trees, stepped out into a narrow, open space. Then he paused abruptly.

On either hand steep, smooth masses of rock jutted up, shutting in the place completely. Less than a score of yards apart, they shelved down into the water, forming a tiny, sheltered cove toward which the ground sloped gently. It was a snug spot, shielded from storms, and also from observation, and a rough shack of weathered boards seemed a natural part of the gray, rock-strewn landscape. But Steve had not been expecting to find a hut here, and his first thought as he stared at it, motionless and a little tense, was to connect it, somehow with the man he was seeking.

For several minutes he stood there alert, his glance fixed curiously and intently on the cabin. It was one of the duck shooters’ huts, no doubt, of which the boys had told him. It must have stood there for some time, too, judging from the dingy, weathered look of the planking. But it seemed odd, with the duck season so far away, that the shutter of the single small window at the rear should be swinging open. Surely any one leaving it for a year or more would have made things more secure against intrusion.

Steve waited a little longer, turning over various possibilities in his mind, and then moved slowly forward. The stillness of the place, coupled with a certain instinct hard to define, made him feel that the shack was at the moment unoccupied. When he reached the window and looked in, he found that instinct had served him well. The place was empty, and after a brief survey, he moved around to the front and opened the door, which was merely on the latch. Instantly his eyes fell upon a raw, splintered spot where a lock had been and he bent to examine it closely.

“Huh!” he grunted. “I thought so. Somebody’s broken in.”

Thoughtfully he straightened up and looked around. There was little doubt in his mind as to who had made the forcible entry, but the object of it was as great a puzzle as the identity of the mysterious stranger. And presently he discovered that there was more than one in the marauding party.

In each of the four rough bunks at one end of the cabin were blankets. Also, scattered over the rude plank table in the middle of the room, were four tin plates and as many cups, all of which had been lately used.

“This is no place for me,” decided Steve as he took in these details. “If they should come back and find me here, I—”

The words clipped off and he whirled about with widening eyes as the muffled beat of an engine’s exhaust smote suddenly on his ears.

“Jimminy!” he gasped, and leaped for the door.

He was half way through it when he saw the bow of a dory sliding into view past the rocks at the end of the cove. Jumping back like a flash, he jerked the door shut and latched it noiselessly. For an instant he hesitated, heart pounding in his throat. Then he moved swiftly to the window, pulled himself up, squeezed through and plunged into the fringe of undergrowth about a dozen feet away.

But as he gained the shelter he realized that the popping of the engine had ceased and he heard the sound of voices. He dared not pause here, but sped on over the