"Mrs. Porter had gone to bed, so I let myself out. I shut the hall door behind me. The window of the room in which they sat was closed, but the blind was not drawn down. There was no change in door or window this morning, or any reason to think that any stranger had been to the house. Yet there they sat, driven clean mad with terror, and Brenda lying dead of fright, with her head hanging over the arm of the chair. I'll never get the sight of that room out of my mind so long as I live."
"The facts, as you state them, are certainly most remarkable," said Holmes. "I take it that you have no theory yourself which can in any way account for them?"
"It's devilish, Mr. Holmes, devilish!" cried Mortimer Tregennis. "It is not of this world. Something has come into that room which has dashed the light of reason from their minds. What human contrivance could do that?"
"I fear," said Holmes, "that if the matter is beyond humanity it is certainly beyond me. Yet we must exhaust all natural explanations before we fall back upon such a theory as this. As to yourself, Mr. Tregennis, I take it you were divided in some way from your family, since they lived together and you had rooms apart?"
"That is so, Mr. Holmes, though the matter is past and done with. We were a family of tin-miners at Redruth, but we sold our venture to a company, and so retired with enough to keep us. I won't deny that there was some feeling about the division of the money and it stood between us for a time, but it was all forgiven and forgotten, and we were the best of friends together."
"Looking back at the evening which you spent together, does anything stand out in your memory as throwing any possible light upon the tragedy? Think carefully, Mr. Tregennis, for any clue which can help me."
"There is nothing at all, sir."
"Your people were in their usual spirits?"
"Never better."
"Were they nervous people? Did they ever show any apprehension of coming danger?"