Halfway there they saw a warning blast of steam rise from the engine, followed by a whistle.

"They'll be pulling out in a minute now!" he gasped, increasing speed.

"We've got to make it!--our only chance!"

"We _will_ make it!" she sobbed through clenched teeth, meeting his pace.

Glancing over his shoulder, after another fifteen seconds, Kendrick saw that the disc was no longer visible. Since there was no vibration he realized with relief that it was now hidden behind the slope they were descending.

"Quick--push your b.u.t.ton!" he said, pushing his own.

They came out of the influence of the invisibility rays, raced breathless on down the slope--gained the station platform just as the train was getting under way.

Helping the exhausted girl aboard, he mounted the steps himself, led her through the vestibule into its single pa.s.senger coach.

Dropping into a seat, they sat there panting as the train gathered speed.

By the time the decrepit but life-saving little local drew into Gila Bend they had somewhat recovered from their harrowing experience.

Marjorie was still pale, however, as Kendrick helped her from the train.

"I may recover," she said with a wan smile, "but I'll never look the same! An old saying, but I know what it means now."

He thought better of a sudden impulse to tell her she looked quite all right to him. Instead, he said grimly:

"I know now what a lot of things mean!"

The Tucson limited would not be through for over an hour, they learned. That would give them time to hunt up the authorities and sound a warning of the ominous invader that was in the vicinity.

Perhaps, by prompt military action, it might be destroyed, or at least crippled.

But first they went to the telegraph office, where Marjorie got off a message that would bring joy to her grieved family.

While standing there outside the barred window, odors of food wafting to them from a nearby lunch-room.

"Um-m!" she sniffed. "That smells good to me! I haven't tasted any earthly cooking for ages. Everything on that horrible disc was synthetic."

"Then I suggest we have ham and eggs, at once," he said. "Or would you prefer a steak?"

"I think I'll have both!"

As they walked into the lunch-room, Kendrick told her of the banquet in his honor Cor had promised for that night.

"I guess I didn't miss much," he ended.

"You certainly didn't!" she a.s.sured him, with a smile. "It would have opened with a puree of split-molecule soup, continued with an entree of breaded electrons, and closed with an ionic cafe."

He laughed.

"I'm just as well satisfied. I was unable to attend! Humble as it is, I think this will prove to be much more wholesome food."

Night had fallen by the time they left the lunch-room. Glancing at his watch, Kendrick saw that they still had better than a half-hour before the limited was due, so they betook themselves to the police station.

It was only a block away and in consequence they weren't long reaching it.

The chief had gone home, the officer at the desk informed them, but if there was anything they cared to report, he would be glad to make note of it.

A big raw-boned westerner, he shifted his quid as he spoke and spat resoundingly in a cuspidor at his feet.

"All right, then--get your pencil ready!" said Kendrick with a smile.

"This is Miss Marjorie Blake, daughter of Henderson Blake, of New York. Perhaps you read of her disappearance, a few weeks ago. And I...."

As he introduced himself and told briefly of their astounding experience, the officer's eyes bulged with amazement.

"Say, what yuh-all tryin' to hand me?" he snorted finally. "D'yuh think I was born simple?"

"Press your b.u.t.ton!" whispered Marjorie. "Show him how the invisibility ray works. It'll save a lot of argument."

"Right!"

He held up his wrist.

"See this? Now watch!"

Whereupon he pressed the b.u.t.ton. But to their dismay, nothing happened.

"Wa-al. I'm still watchin'!" drawled the officer. "Who's loony now?"

Kendrick examined the mechanism in impatience, pressed that little b.u.t.ton repeatedly: but still nothing happened.

"Try yours!" he told Marjorie finally.

She did so, with similar results--or lack of them, rather.

"Something's wrong," he said at length. "The ray isn't working."

"Wrong is right!" declared the officer with a contemptuous flood of tobacco juice. "Yuh folks better go catch yuhr train 'fore yuh ferget where it is."

Chagrined, embarra.s.sed, they took their leave, headed back toward the railroad station.

"Of all the utterly silly things!" declared Marjorie, as they walked along. "Why do you suppose it didn't work?"

Kendrick didn't reply at once. When he did, his voice was grave.

"Because the disc has gone!" he said. "We are outside its zone of influence. That's my hunch, at least, and I think we'd better act on it."