Because of that flitting shadow I had seen, I knew this place was not impervious. Some one person, at least, could enter and leave the room easily, quickly, while its doors were locked. But that might be Hughes--or even Worth--with some reason for doing so not willingly explained, and some means not readily seen. It probably had nothing to do with Thomas Gilbert's sudden death, could not offset in my mind the conviction of Thomas Gilbert's stiffened fingers about the pistol's butt. That I made a second thorough investigation of the study interior was not because I questioned the manner of the death.
I began taking down books from the shelves at regular intervals, sounding the thick dead-wall, in search of a secreted entrance. I came on a row of volumes whose red morocco backs carried nothing but dates.
Worth turned his head to look, and the bleakest thing that could be called a smile twisted his lips a little, as he said,
"Yes. He'd kept diaries for thirty years."
"But he seems to have dropped the habit. There is no 1920 book."
"Oh, yes there is," very definitely. "He never gave up setting down the sins of his family and neighbors while his eyes had sight to see them, and his hand the cunning to write." He spoke with extraordinary bitterness, finishing, "He would have had it on the desk there. The current book was always kept convenient to his hand."
"Worth," I asked, "did you see that 1920 volume when you were here last night?"
He looked a little startled, and I prompted,
"Were you too excited to have noticed a detail like that?"
"I wasn't excited; not in the sense of being confused," he spoke slowly. "The book was there; he'd been writing in it. I remember looking at it and thinking that as soon as I was gone, he'd sit down in his chair and put every damn' word of our row into it. That was his way. The seamy side of Santa Ysobel life's recorded in those books. I always understood they amounted to a pack of neighborhood dynamite."
He nodded listlessly. I went to it, giving that room such a searching as would have turned out a bent pin, had one been mislaid in it. I even took down from the shelves books of similar size to see if the lost volume had been slipped into a camouflaging cover--all to no good. It wasn't there. And when I had finished I was positive of two things; the study had no other entrance than the apparent ones, and the diary of 1920 had been removed from the room since Worth saw it there the night before. I reached for one of the other volumes. Worth spoke again in a sort of dragging voice,