“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?”