Jacques Futrelle,
The Thinking Machine — The Flaming Phantom
(1907)
“ I knew—the pure logic of it told me—how the ghost was made to appear and disappear; one look at the house inside convinced me beyond all doubt. I knew the motive for the ghost—a search for the jewels. I knew, or thought I knew, the name of the man who was seeking the jewels; the man who had fullest knowledge and fullest opportunity, the man whose brain was clever enough to devise the scheme. Then, the next step to prove what I knew. The first thing to do was to find the jewels.”“Find the jewels?” Weston repeated, with a slight smile.“Here they are,” said The Thinking Machine, quietly. ”
