that city."

The flier wabbled, as Haynes' hands on the controls wabbled.

"What city?" he asked in an odd voice.

Wentworth stared unbelievingly. There was nothing in sight but the lunatic rows of skit-trees, stretching out with absolutely mechanical exactitude to the limit of vision on the right, on the left, ahead, and behind to the very base of the mountains. There simply wasn't any city. Wentworth gaped.

"Pull that film out of the camera. Take a look at it. Were we seeing things?"

Haynes pulled out the already-developed film. The city showed plainly. It had gone on television to the Galloping Cow, too. It had not been an illusion. Wentworth pushed the call-button again as the flier went on toward a vanished destination. After a moment he swore.

"McRae lost no time. He's out of air already, and our set won't reach him. Where'd that city go?"

He set the supersonic collision-alarm in action. The radar. They revealed nothing. The city no longer existed.

They searched incredulously for twenty minutes, at four hundred miles an hour. The radar picked up nothing. The collision-alarm picked up no echoes.

"It was here!" growled Wentworth. "We'll go back and start over."

He sent the flier hurtling back toward the hills and the embankment where it had rested during the night. The communicator rasped a sudden furious burst of static. Wentworth, for no reason whatever, jerked his eyes behind. The city was there again.

Haynes photographed it feverishly as the flier banked and whirled back toward it. For a full minute it was in plain view, and the static was loud. Then the static cut off. Simultaneously, the city vanished once more.

Again a crazy circling. But the utterly monotonous landscape below showed no sign of a city-site, and it was impossible to be sure that the flier actually quartered the ground below, or whether it circled over the same spot again and again, or what.

"If McRae turns up in the Galloping Cow," said Haynes, "and doesn't find a blamed thing, maybe he'll think we've all gone crazy and had better go home. And then—"

"Then you'll get married!" Wentworth finished savagely. "Skip it! I've got an idea! Back to the 

 Prev. P 7/17 next