He walked on and on, slowly, uncertainly, until the beach and the sea began to waver like a heat mirage. And suddenly the shells and the water vanished and he was on the green grass again with the grove of trees just ahead. He turned, saw a white highway with his car parked on the shoulder.

Dazedly, Sutter walked back to the car....

All next morning he ruminated over his strange experience. Toward noon the pieces of the puzzle began to fit slowly together in his mind. But the partial answer at which he arrived seemed too fantastic for belief. Could it be possible that when he had stopped at the roadside stand he had blundered, in some inexplicable way, into another dimension?

Sutter had a layman's knowledge of Einsteinian physics, and he knew that experiments in Time were being made every day. Only last week he had read in the paper of an army officer who had reportedly Time-traveled some twenty-two minutes. And a year ago the Belgian scientist, Delgar, claimed to have entered a secondary world which he declared impinged on our own.

Assuming all this to be true, then it could be that the Tanganyika television set was a product manufactured in Future Time by a company that, by Sutter's Time standards, didn't yet exist.

The following day saw Sutter begin an experiment of which he was rather proud. Travail had said that he had tried to tune in the noon news broadcast yesterday on the TV and had turned the set on from twelve o'clock until five minutes after. At a nearby appliance store Sutter purchased a clock control which would turn his television set on and off at any chosen time. He set the control for two o'clock, then managed to lure Travail out of the house for the afternoon by giving him an invitation he'd received for a lecture on marine life at a local club. Next, he drove again to the H-bomb site and stood waiting in the grass-like park, watch in hand.

At precisely two o'clock there came that queer staggering of earth and sky. The trees gave way to the stretch of sand; the waves, leaden-colored and cheerless, dotted with white caps rolled up on the lonely shore. As before Sutter felt that same exhilaration, that same reversal to the spirit of his youth. But despite his mental excitement he maintained an awareness of the situation and a remembrance of why he had come here.

When he walked among the shells this time he carried a large basket with him and he picked up shells and dropped them into the basket, selecting those that were the most alien.

In due time the basket was filled to overflowing and Sutter stood still, waiting. Once more the surrounding landscape underwent its change. After the whirling had ceased and the initial feeling of vertigo had passed Sutter carried the full basket back to the car and began the long drive home.

As he drove he mused over what Travail would say when he saw these shells. Then on second thought, he decided not to show them to him. Travail was getting on his nerves. He had obviously lied about his interest in shells. On discussing the subject with him Sutter found he did not know the first thing about them. In fact, he regretted taking him in as a roommate.

He was convinced that Travail's friendly good-fellowship attitude was just a pose, cloaking a so far mysterious motive. But it could be that Travail knew of the value of Sutter's shell collection. Yesterday a letter had come from the Federal Arts Museum offering five thousand credits for the lot, and while he had made no mention of the amount, Sutter had been foolish enough to tell Travail there had been an offer.

"Are you going to sell?" Travail had asked.

"Certainly not. They're worth five times the price they offered."

"Are they really?" said Travail. "That makes my own collection seem worthless by comparison."

Oh, Travail could be clever all right! Why else had he made no comment about the alien shells they both had seen on the television set, if he did know something of the value of shells?

Arriving home, Sutter