"You mean...?"

"I mean our escape has probably caused them to hurry their plans.

They're probably over New York right now. I think we'd better get there the quickest possible way."

The result was that when the train came, they remained on it only to Tucson. There they chartered a fast plane and started east at once.

At sunset the following day the plane swooped out of the sky and slid to rest on the broad grounds of the Blake estate at Great Neck.

As Kendrick stepped from the cabin and helped Marjorie down, a tall, distinguished-looking man with graying hair and close-cropped mustache came hurrying toward them.

"Daddy!" she cried, rushing into his arms. "Oh, Daddy--Daddy!"

Even without this demonstration. Kendrick would have recognized Henderson Blake from pictures he had seen recently in the papers.

Now he was introduced, and Blake was gripping his hand warmly.

"I don't quite know what this is all about, Professor," he heard the great financier say. "Marjorie's telegram last night was as cryptic as it was over-joying. But I do know that I owe you a deep debt of grat.i.tude."

"Yes, and you owe our pilot about a thousand dollars, too!" put in the daughter of the house, clinging to her father's arm. "Please give him a check--then we'll go inside and I'll explain all about it."

"A matter very much easier dispatched than my debt to Professor Kendrick," said Blake, complying.

The check was for two thousand, not one, the pilot saw when he received it.

"Thank you very much, sir!" he said, saluting.

"Don't mention it. Good night--and good luck to you!"

The pilot returned to his plane, it lifted from the lawn, droned off into the twilight.

Then they approached the cool white villa that stood invitingly a hundred yards or so away beyond sunken gardens.

As they neared it, a handsome, well-preserved woman whose face reflected Marjorie's own beauty came toward them. Lines of suffering were still evident around her sensitive mouth, but her dark eyes were radiant.

"Mother!"

"My poor darling!"

They rushed into each other's arms, clung, sobbing and laughing.

Kendrick was glad when these intimate greetings were over and he had met Mrs. Blake.

They were in the drawing-room now, listening to a somewhat more lucid account of their daughter's experiences and those of her rescuer.

Marjorie was doing most of the talking, but every now and again she would turn to Kendrick for verification.

"Heavens!" gasped Mrs. Blake, finally. "Can such things be possible?"

"Almost anything seems possible nowadays, my dear," her husband told her. "And you say, Professor, that you have brought back samples of this invisibility device?"

"Yes, we have, but I can't promise they'll work. I'll try, however."

Whereupon, sceptically, he pressed that little square b.u.t.ton--and instantly faded out of sight.

"Good Lord!" cried Blake, leaping to his feet. "That proves it! Why, this is positively--"

His remarks were cut short by a scream of terror from his wife.

"Marjorie--Marjorie!" she shrieked.

Wheeling, he faced the chair where his daughter had sat. It was empty, so far as human eyes could see.

"Don't worry Mother--Daddy!" came a calm voice from it. "I'm quite all right--coming back--steady."

And back she came, as did Kendrick, from the empty chair beside her.

His face was grave. The success of the demonstration, which had proved their story to practical-minded Henderson Blake, had proved to him something altogether more significant. The disc, as he had surmised, had rushed eastward immediately on learning of their escape, and was now probably hovering right over New York.

"Marvelous--marvelous!" declared Blake. "But that heat ray, Professor.

That sounds bad. You are convinced it is as powerful as they make out!"

"Positively! That blast they let go in the desert would have utterly destroyed New York."

"Hm! Yes, no doubt you're right. I fully realize how the fearful menace of this thing. Do you think the military authorities will be able to cope with it?"

"I don't know. Perhaps, if they are prompt enough."

"And is there no other way--no scientific way?"

Kendrick grew thoughtful.

"I wonder," he said at last. "There's just a possibility--something running through my mind--an experiment I'd like to make, if I had the facilities of some large electrical laboratory."

"You shall have them to-morrow!" Blake promised. "I'm one of the directors of Consolidated Electric. Their experimental laboratory in Brooklyn is the finest of its kind in America. I'll see that you have the run of it."

"That will be very kind," said Kendrick. "But don't expect anything to come from it, necessarily. It's just a theory I want to work out."

A butler entered at this moment and announced dinner.

"Well, theories are mighty these days!" beamed Blake, as they rose, clapping the younger man on the shoulder. "You go ahead with your theories--and I'll bring a few facts to bear. To-morrow noon I'll escore some military men and others of my friends over to the laboratory to hear and see something of this menace direct. Meanwhile, and during this crisis, it will honor me to have you as my guest."