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 button--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.