that it seems unlikely that he visited any intermediate spot."

"But he may not have been in the crate when Bolton and I saw it."

"I don't believe he was in the crate then," replied Gatton, "but I
think he was at the Red House nevertheless."

I stared at him with curiosity.

"You mean that he was in the house at the time that the constable and
I opened the garage?"

"I do. I think he was in that room where supper was laid for two."

"Good God!" I exclaimed; for there was something horrible in the idea
of the man who now lay murdered having been in the house presumably
alive, whilst Bolton and I had stood within forty yards of him; in the
idea that it had lain in our power, except for those human limitations
which rendered us ignorant of his presence, to have averted his fate,
perhaps to have checked the remorseless movement of this elaborate
murder machine which seemingly had been set up in the Red House.

"Some one was here last night," declared Gatton suddenly, as we turned
to leave the deserted room, "after you and Bolton had gone. Everything
incriminating the assassin has been removed. Looking at the matter
judicially, it becomes quite evident that any one clever enough to
have planned this crime could not possibly have been guilty of an act
of such glaring stupidity as that of accidentally leaving a photograph
planted upon the mantelpiece."