"Then I must, though I do not think you will comprehend or even believe me. Briefly, it is this: yesterday morning I was working on the final series of experiments with a new type of harmonic overtones plus a new type of sinusoidal current which I had arranged with a series of selenium cells. When I finally threw the switch—remember, I was many weeks preparing the apparatus, and had just put the final touches on early that morning—there was a sound such as never had been heard before by human ears, an indescribable sound, terrifying and mysterious. Also, there was a fierce, devouring verditer blue light, and this came from the plates and studs you see, but so great was its strength that it got out of control and leaped about the room like a live thing. For some moments, while it increased in intensity as I raised the power of the current by means of the switch I held in my hand, I watched and listened in fascination. My instruments had ceased to record, though they are the most delicate ever invented and can handle almost anything which man can even surmise."
he perspiration was pouring from Lambert's face, as he recounted his story. The detectives listened, comprehending but a little of the meaning of the scientist's words.
"What has this to do with Miss Crawford?" asked Doherty impatiently.
Phillips held up his hand to silence the other sleuth. "Let him finish," he ordered. "Go on, professor."
"The sensations which I was undergoing became unendurable," went on Lambert, in a low, hoarse voice. "I was forced to cry out in pain and confusion.
"Miss Crawford evidently heard my call, for a few moments later, just as the terrific unknown force reached its apex, she dashed into the laboratory, and stepped across the plate you see there.
"I was powerless. Though I shut off the current by a superhuman effort, she—she was gone!"
Lambert put his face in his hands, a sob shook his broad shoulders.