"You know your orders, Frisk," they heard the one with the weasel-like face say. "When you get the signal-"

He broke off as his gaze fastened upon Dan and Brad. The Cubs instantly looked away but Paper Bag Eddie's suspicions had been aroused.

Shoving back his chair, he walked over to the booth.

"Say, what's the idea?" he demanded in a soft, purring voice.

"I don't know what you mean," Brad returned, meeting his gaze steadily.

"You followed me in here. Now you're trying to eavesdrop."

"This is a free country," Brad retorted. "If my friend and I want to come in here for a sandwich, I'd like to see you stop us!"

"You would, eh?" the man replied, his lips parting in an ugly smile. He grasped Brad by the shoulder, pulling him half-way out of the booth. "Who are you and what's your game?"

Before Brad could answer, the proprietor of the Green Parrot came quickly from the direction of the kitchen. He had seen what was happening and did not want any trouble in his place.

"Cut it out, Eddie," he said. "No rough stuff here."

"Who are these kids?"

"How should I know? Never saw 'em before."

"They were standing outside the cafe, watching," Eddie informed the proprietor. "When we came in, they followed. I say, throw 'em out."

The proprietor hesitated, reluctant to antagonize either party.

"Throw 'em out!" Paper Bag Eddie repeated in a tone not to be denied.

"I'm sorry, boys," the proprietor apologized. "I don't want any trouble here. I'm afraid I'll have to ask you to leave."

"We'll go," Brad said. "Come on, Dan."

In sliding out from the booth seat, Dan bestowed another glance upon the man Paper Bag Eddie had called "Frisk." More than ever he was convinced that he had not been mistaken in identifying him as the motorboat operator.

"I've seen you before," he said, halting beside the table. "You were handling the wheel of the motorboat that struck our dinghy!"

"That's a lie!" the florid-faced man rasped. "I never set eyes on either of you before-and what's more, I don't want to again. Now if you know what's healthy, get out of here!"

Dan would have stood his ground, but Brad grasped his arm, pulling him firmly along. The proprietor followed the two boys to the door.

"I'm sorry," he apologized once more. Then in an undertone, he added: "Don't come back. For some reason Eddie has taken a dislike to you-and when he's crossed, he's bad medicine!"

CHAPTER 6 Stranded

Three days elapsed during which Brad, Dan and the other Cubs spent much time at the "Y" and at the river practicing for the final swimming meet of the year with Den 1.

Annoyed by the manner in which they had been treated by Paper Bag Eddie and his friend "Frisk," the two Cubs interested themselves in making a few inquiries along the waterfront.

They learned that a sailor by the last name of f.a.gan frequently was seen with Eddie. Although known to have no employment, he was reported always with enough money in his pocket.

"I'm as sure as anything f.a.gan was in the motorboat that struck us," Dan repeated to Brad one afternoon when the two boys were at the river preparing for a swim. "I suspect that was why he acted so sore in the cafe. He was afraid we'd accuse him."

Since their meeting with Paper Bag Eddie and the sailor, the two Cubs had not seen either of them again. Nor had they glimpsed Mr. Manheim's boat or any that resembled it.

On this particular afternoon, Mr. Holloway had promised to take Brad, Dan and Midge for a sail. Four o'clock, the hour appointed for their meeting at the Yacht Club dock, came and went. Finally, Mr. Holloway telephoned from his office to say that he had been held up and would be unable to make the excursion.

"There's no reason why you boys can't take the boat by yourselves," he urged. "You're both experienced at handling the tiller, and good swimmers. Go ahead! Only don't go too far from the Yacht Club. A storm could kick up before dusk."

Fortifying themselves with bottles of pop, Dan and Brad hoisted sail and cast off. With Brad at the tiller, they sailed down the channel, past Fish Island, and on toward Skeleton Island. They had been anxious to explore this island for some time.

Dan lounged in the bottom of the boat, lazily sipping his drink.

"Let's sail all the way around Skeleton Island," he proposed. "Okay?"

"Sure, if we have time," Brad agreed, glancing at the darkening sky.

"Those clouds are rolling up rather fast though. We might have rain in a couple of hours."

"We'll make it back before then," Dan replied, stretching luxuriously.

"The breeze is just right now."

In a long tack, they crossed to the far sh.o.r.e of the river and came about, pointing toward Skeleton Island.

As Dan dropped an empty pop bottle overboard, he noticed a mahogany motorboat almost directly opposite the island.

The craft had pulled up along sh.o.r.e, its motor idle. The boy was unable to see the occupants or to obtain a clear view of the boat itself, for it lay half-hidden in a clump of bushes.

"That boat looks a little like Mr. Manheim's," he remarked, calling Brad's attention to it. "Wonder what it's doing over there? No one appears to be fishing."

Holding the sailboat to its course, the two Cubs kept watch of the idle motorboat. Though they were too far away to be certain the craft was Mr.

Manheim's, they thought it bore a marked resemblance to the craft operated by Wilson Jabowski.

Presently, as the boys watched, they saw someone aboard the motorboat lower and raise a red flag three times in succession.

"What's the idea of that?" Dan demanded, all attention. "They're signaling!"

"To someone on Skeleton Island," Brad added quietly.

Dan turned his gaze toward the island beach. A man stood there, apparently focusing his attention upon the motorboat. In answer to the signal, he raised and lowered his arm three times.

"What goes?" Brad muttered.

For awhile, the Cubs witnessed nothing more of interest. The man on the beach vanished from their range of vision, while the motorboat remained in the clump of bushes.

"Guess there's nothing more to see," Dan remarked in disappointment.