Once more Steve was in the cleft, and a few seconds later he was moving slowly up between the walls. Pitch watched him for a few moments, and then, when it was obvious that Steve wasn’t going to wait for him or turn back, Pitch hesitantly started up himself. He found it easier than he had expected as long as he kept his back hard against the opposite wall and his feet firmly in the cuts. Soon he was gaining upon Steve, who had to spend time uncovering each cut before going on.

As Steve neared the top he could see the wide ledge above. He pushed himself up the remaining few feet and then crawled out upon it. Pitch was just behind, and Steve reached down to help him up.

They stood there side by side, looking about them. Below was a precipitous drop to the sea, and above another sheer wall of yellow stone. Pitch had begun to shake his head dismally when he saw the box-shaped stone that rose a few feet above the center of the ledge. “Look here, Steve,” he said, running to it.

When Steve joined Pitch, he found him looking down a darkened shaft. The hole was about four feet in area, and the stone around it was squared off at each corner, “Somebody built this,” Steve said, looking down into the blackness of the hole. “What is it? Where does it go?”

Pitch was running his hands around the sides. “This isn’t stone,” he said. “It’s a mortar of some kind. See how it crumbles, Steve. I’d say it’s hundreds of years old.”

“What’s the hole for?”

“I don’t know for sure. But it could be a ventilation shaft,” Pitch returned.

“You mean to tunnels below?” Steve asked. “Tunnels that may lead to the interior of the island?”

“Your guess is as good as mine, Steve,” Pitch replied quickly. “We’ve really stumbled onto something.”

Looking down the shaft, Steve said, “How deep do you think it goes, Pitch?”

Pitch looked about the ledge. “If we had something to drop we could tell approximately,” he said. They searched the ledge but could find nothing on the bare rock; then Pitch put his hand in his pockets and finally withdrew a long piece of white chalk. “This will do,” he said. “I must have picked it up at the Customs office when you arrived.” Leaning over the shaft, he added, “Listen closely now,” and dropped the chalk.

Steve heard Pitch counting to himself as the chalk fell; then came the soft thud as it struck the bottom of the shaft.

Pitch said, “About a hundred feet, Steve, as close as I can figure it.”

“The rope could easily do it then,” Steve said quickly.

“You mean for us to go down?” Pitch asked, his eyes becoming grave. “You think we should, Steve? We don’t know what we’ll find below. It might be dangerous.”