"I think I've told you everything," she said. "I don't think there was anything else. When I answered the 'phone, the voice asked if I were Polly Wickes, and kept on repeating my name over and over again in a horrible, crazy, sing-songy way, and then I heard a sound as though a door had been blown open by the wind, and I could hear the waves pounding, and then the door was evidently slammed shut again, and the voice said what I—I have told you about wearing black for my mother. And then I couldn't hear anything more, and I couldn't get any answer, though I called again and again into the 'phone. Oh, guardy, I can't understand! I—I'm sure it was the same voice as that other night. What does it mean? Guardy, what should we do? Who could it be?"

A door blown open by the wind! The pound of the waves! Where was there a telephone that would measure up to those requirements? Not in the house! Captain Francis Newcombe smiled grimly in the darkness. The private installation was restricted to the house and its immediate surroundings. Therefore the boathouse! The boathouse had a 'phone connection. And there was still an hour or more to daybreak! But first to shut Polly's mouth.

"Polly," he said gravely, measuring his words, "I haven't the slightest doubt but that it was the same voice we heard in the woods; in fact, I'm quite sure of it. And I'm equally sure now that I know who it is."

She drew back from him in a quick, startled way.

"But, guardy, you said it was only some one catcalling to—"

"Yes; I know," he interrupted seriously. "But I did not tell you what I was really suspicious of all along. With what I had to go on then, it did not seem that I had any right to do so. It's quite a different matter now, however, after what has happened to-night."

"Yes?" she prompted anxiously.

"There can be only two possible explanations," he said. "Either some one is playing a cruel hoax; or it is the work of an unhinged mind, an irrational act, a phase of insanity that—"

"Guardy!" she cried out sharply. "You mean—"

"Yes," he said steadily; "I do, Polly. And there can really be no question about it at all. Can you imagine any one doing such a thing merely from a perverted sense of humour?—any one of us here?—for it must have been some one of us who is connected with the household in order to have had access to a telephone. It is unthinkable, absurd, isn't it? On the other hand, the hour, the irresponsible words, their 'crazy' mode of expression, as you yourself said, the motiveless declaration of a palpable untruth, all stamp it as the work of one who is not accountable for his actions—of one who is literally insane. And then the fact that you recognised the voice as the one we heard two nights ago is additional proof, if such were needed, which it very obviously is not. You remember that we had seen Mr. Marlin in his dressing gown disappear under the verandah a few minutes before we heard the calls and cries and wild, insane laughter. My first thought then was that it was Mr. Marlin, and I was afraid that either harm had, or might, come to him. I sent you at once back to the house, and I ran into the woods to look for him. I did not find him; and, therefore, as there was always the possibility then that I had been mistaken, I felt that I should not alarm any of you here, and particularly Miss Marlin, by suggesting that Mr. Marlin's condition was decidedly worse than even it was supposed to be. Is it quite plain, Polly? I do not think we have very far to look for the one who telephoned you to-night."