Angry to think that the intruder had dared to risk injuring them by deliberately hurling a stone, the Cubs started after him.

Already the man was far away, moving with cat-like tread through the dense growth of vines and underbrush. Apparently familiar with the terrain, he slipped between the trees like a shadow.

"No use trying to follow," Dan decided after they had gone only a few yards. "We've already missed our chance to see who he was."

"And if we trail him a long distance from camp, he might try some of his tricks," Chips added in an undertone. "Dan, that man's face scared me. He looked downright ugly."

"He did," Dan agreed. "I only caught one glimpse of his face, but that was enough."

"Ever see him before?"

"N-o-o," Dan replied slowly. "For just a minute I thought-"

The boy was on the verge of saying that the man had resembled "Frisk,"

the a.s.sociate of Paper Bag Eddie. However, his identification had been most uncertain.

"You thought what, Dan?"

"Oh, nothing. I didn't really see the man's face plainly. Wonder why he'd try to harm us?"

"Let's report to Mr. Hatfield."

To this suggestion, Dan promptly agreed. Picking their way back to the pool, the boys made short work of filling the water pail and gathering clay.

Back in camp once more, they took Mr. Holloway and the Cub leader aside to relate what had happened.

"The man actually hurled a stone?" Mr. Hatfield questioned, his face sober.

"He certainly did," Dan confirmed. "It missed my head by inches."

Very much disturbed, Mr. Hatfield and Midge's father warned the two boys to make no mention of the incident to the other Cubs.

"I'll take Mr. Suell and explore the island," the Cub leader decided.

"Mr. Holloway will remain in camp with the boys. Without letting them know that anything is amiss, keep them there."

"It soon will be supper time," Mr. Holloway agreed. "I'll find enough work to occupy their time."

Mr. Hatfield and Mr. Suell set off at once to search for the stranger who had accosted the boys at the spring.

Meanwhile, Chips and Dan helped with supper preparations, trying not to reveal their inner excitement to the other Cubs. As time wore on and neither the Cub leader nor Mr. Suell returned, it became increasingly difficult to contain their secret.

The boys were nearly through supper when the two finally appeared in camp. Slipping almost unnoticed into the group around the fire, they dished up their own suppers.

"Learn anything?" Dan asked the Cub leader in a whisper.

"Tell you later." Mr. Hatfield's glance warned the boy to say no more at the moment.

In silence, but with no show of uneasiness, the Cub leader ate his supper. While the other boys were clearing away the dishes, he took Dan, Brad and Chips aside to relate what he and Mr. Suell had noted in their explorations.

"Did you find that fellow we saw by the spring?" Chips questioned before Mr. Hatfield could speak.

"No, Chips. We tramped the island from one end to the other. Not a sign of him."

"No signs?" Dan echoed.

"My statement wasn't quite accurate," Mr. Hatfield corrected. "We found signs in the way of footprints, a well-beaten trail, and broken bushes.

But we failed to catch up with the man himself."

"Where did the trail lead?" inquired Chips.

"We picked it up by the spring and followed it the entire length of the island through the woodland and marsh. It emerged not far from the old hotel."

"Maybe the fellow hid in there," Dan suggested.

"That's what Mr. Suell thought. We looked the place over, but couldn't get in. All the doors were locked and the blinds drawn. If Mr. Jabowski looks after the place for Mr. Manheim, he doesn't hurt himself working at the job."

Having told the boys everything he and Mr. Suell had learned, the Cub leader again warned them to say nothing of the affair to the other boys.

"Frankly, I can't figure out why anyone would hurl a stone without provocation," he said. "I'm afraid someone may be annoyed because the Cubs have camped here."

"But we had a perfect right to do it," Dan protested.

"Of course. Mr. Manheim granted permission. But things may be going on here of which he has no knowledge."

"For instance?" interposed Brad.

"I can't say, because I don't know. It's just a feeling I have. Mr. Suell and I will take turns guarding the camp tonight."

"Then you think the Cubs may be in danger here?" Brad asked, startled.

"No, Brad, if I thought so, we'd break camp and pull out tonight. We'll set up a watch as a precaution. First thing in the morning, I'll go to the mainland to have a talk with Mr. Manheim."

After the camp work was out of the way, the Den Dads built a huge fire on the beach. Mr. Suell then gave the boys a brief talk on Cubbing in other countries of the world, telling them that the organization extended to 50 lands.

"And are the ideals and aims the same everywhere?" Brad questioned, tossing another stick of wood into the flames.

"Practically so, Brad. In most countries, the Kipling Jungle stories have been made the basis of Cubbing. Akela is the name of the Cub leader in nearly all nations. The two-fingered sign of the Wolf is the Cub sign around the world."

Dan, who lounged on the sand beside Brad, had listened with keen interest. But now his attention wandered.

Beyond the rim of flickering light, he thought he saw movement. Was that shadowy form a trick of wind and tree boughs? Or might someone be spying upon the camp?

"Wake up, Dan!" Brad nudged him hard in the ribs. "Mr. Hatfield just asked you to lead in the singing of 'Cheer, Cheer, the Den's All Here.'

Are you asleep?"

Dan tore his eyes from the area of darkness. After all, he told himself, he probably had fancied the shadow. Imagination played strange tricks upon a fellow.

"Sorry," he apologized. "I didn't hear. Guess I was half asleep."