Delighted, forgetting everything else, Proteus ran down the hill as fast as he could go. The rocky ground hurt his feet. Brambles caught his clothes. He hardly noticed. Twice he dropped his survival kit, picked it up automatically, and ran on. What kind of people had lived there and when? The area was being worked; some machinery stood silently nearby.

Then off to the side he saw buildings, ruins in better shape than elsewhere, that looked inhabited. Rough material hung at the windows. Perhaps laborers or archeologists stayed there. Cautiously, Proteus stopped, then set out in the opposite direction, walking as quietly as he could.

It didn’t take him long to come to the largest rock platform in the middle of the dig. As soon as he approached, a small dog ran suddenly out from behind a broken statue of a man. Proteus knew it was a dog though he’d only seen them in zoos, so he ran after it. The dog never barked, though it might, Proteus thought suddenly, and awaken whoever might be sleeping at the dig. Instead … could he be mistaken? … No, the dog was trying to lead him somewhere. It kept wagging its stubby tail, and running to him, then back to the statue.

Finally Proteus followed. A round hole was visible beside the statue, and the dog ran down a flight of stairs beneath. Proteus couldn’t tell how deep the hole was, for the stairs turned, but already the dog had disappeared.

An open invitation? A trained dog? Did it belong to the man who’d contacted him on TV? Was it a trap? Proteus’ arguments with himself were only academic, and he knew it. Already he had taken his first step down. A trapdoor within the Earth, on the other side of the surface—he’d never really expected to see any such thing. After traveling down in the skylevator to the ground, what an opportunity now to descend ever further, inside it!

But where had the dog gone? When Proteus went down perhaps ten of the stone steps, a noise attracted his attention just as the light suddenly changed. Whipping around, he was just in time to see the hole close above him, and a round arc of blackness shut out the morning sky. It was only then that he realized that the steps were dimly lighted. Simultaneously he wondered if the statue above had changed position and stood now solidly atop the hole.

Again his excitement conquered his fear—almost. Only now and then his scalp prickled and the blood pounded alarmingly loud in his ears. For one thing, he’d never smelled such odors before, a mixture of minerals and moisture and thickly packed dirt, long untouched—a musty yet evocative pungency that kept reminding him that he was actually on the other side of the Earth’s surface.