Jerry and Penny kept quiet as the man turned the door k.n.o.b. He heaved angrily against the panel with his shoulder.

"Hey, Jake," he shouted, "what's the idea of locking the door?"

"I didn't lock it."

"Then Flora did." Muttering under his breath, the seaman tramped back up on deck.

Perhaps ten minutes elapsed before Penny and Jerry heard a feminine voice speaking.

"That must be Flora," whispered Penny. "What will happen when she tells them that she didn't lock the door?"

The voices above rose louder and louder until the two prisoners were able to distinguish some of the words. Jake berated the girl as stupid while his companion showered abuse upon her until she broke down and wept.

"I never had the key," they heard her wail. "I don't know what became of it. You always blame me for everything that goes wrong, and I'm good and sick of it. If I don't get better treatment I may tell a few things to the police. How would you like that?"

Jerry and Penny did not hear the response, but they recoiled as a loud crashing sound told them the girl had been given a cruel push into a solid object. Her cry of pain was drowned out by another noise, the sudden clatter of the motor boat engine.

Penny and Jerry gazed at each other with startled eyes.

"We're moving," she whispered.

Jerry started to fit the key into the door lock, only to have Penny arrest his hand.

"Let's stay and see it through," she urged. "This is our chance to learn the hide-out and perhaps solve the mystery of Atherwald's disappearance."

"All right," the reporter agreed. "But I wish you weren't in on this."

From the tiny window of the cabin, he and Penny observed various landmarks as the boat proceeded downstream. Perhaps half an hour elapsed before the cruiser came to the mouth of a narrow river which emptied into the Kobalt. From that point on progress became slow and often the boat was so close to sh.o.r.e that Penny could have reached out and touched overhanging bushes.

"I didn't know this stream was deep enough for a motor boat," Jerry whispered. "We must be heading for a hide-out deep in the swamp."

"I hope Salt has sense enough to call Dad and the police," Penny said with the first show of nervousness. "We're going to be a long way from help."

The boat crept on for perhaps a mile. Then it stopped, and Penny a.s.sumed they had reached their destination. Gazing out of the window again, she saw why they were halted. A great tree with finger-like branches had fallen across the river, blocking the way.

"Look, Jerry," she whispered. "We'll not be able to go any farther."

"Guess again," the reporter muttered.

Penny saw then that one of the men had left the boat and was walking along sh.o.r.e. He seemed not in the least disturbed by the great tree and for the first time it dawned upon her that it served a definite purpose.

"Lift 'er up, Gus," called the man at the wheel of the boat.

His companion disappeared into the bushes. Several minutes elapsed and then Penny heard a creaking sound as if ropes were moving on a pulley.

"The tree!" whispered Jerry, his eyes flashing. "It's lifting!"

Very slowly, an inch at a time, the great tree raised from the water, its huge roots serving as a hinge. When it was high enough, the motor boat pa.s.sed beneath the dripping branches and waited on the other side.

Slowly, the tree was lowered into place once more.

"Clever, mighty clever," Jerry muttered. "Anyone searching for the hide-out would never think of looking beyond this fallen tree. To all purposes nature put it here."

"Nature probably did," Penny added. "But our dishonorable friends adapted it to their own use."

Through the window Penny saw the man called Gus reboard the boat.

Once more the cruiser went on up the narrow stream, making slow but steady progress. Long shadows had settled over the water. Soon it became dark.

Then a short distance ahead, Jerry and Penny observed a light. As the boat drifted up to a wharf, a man could be seen standing there with a glowing lantern. They were unable to see his face, and quickly dodged back from the cabin window to avoid being noticed.

"Everything all right, Aaron?" the man at the wheel asked, jumping ash.o.r.e. He looped a coil of rope about one of the dock posts.

"Aaron!" whispered Penny, gripping Jerry's hand.

"It must be Aaron Dietz, Kippenberg's former business a.s.sociate. So he's the ringleader in this business!"

They listened, trying to hear the man's reply to the question which had been asked.

"Yeah, everything's all right," he responded gruffly.

"You don't sound any too cheerful about it."

"Atherwald still won't talk. Keeps insisting he doesn't know where the gold is hidden. What bothers me, I am beginning to think we made a mistake. He may be telling the truth."

"Say, this is a fine time to be finding it out!"

"Oh, keep your shirt on, Gus. You and Jake will get your pay anyhow. And even if Atherwald doesn't know the hiding place we'll make Kippenberg come through."

"You'll have to find him first," the other retorted. "If you ask my opinion, you've made a mess of the whole affair."

"No one asked your opinion! We'll make Atherwald tell tonight or else--"

The man with the lantern started away from the dock but paused before he had taken many steps.

"Get those supplies up to the shack," he ordered. "Then I want to talk with you both."

"All right," was the reply, "but we have to get the cabin door open first. Flora locked it and lost the key."

"I didn't," the girl protested shrilly. "Don't you try to blame me."

Jerry and Penny knew that their situation now was a precarious one. If they were found in the cabin they would be taken prisoners and the exclusive story which they hoped to write never would be theirs.

"We've trapped ourselves in this cubby-hole," the reporter muttered. "All my doing, too."

"We can hide in the closet, Jerry. The men may not think to search there."

Noiselessly, they opened the door and slipped into the tiny room. The air was hot and stuffy, the s.p.a.ce too narrow for comfort.