"Where?"
"In the shed on the Castle Down. Now, how the deuce did it get there? The dead sailormen had no use for keys."
"It's very curious," said Dick.
"Very curious and freakish," said I, and I sat down on the grass to think the matter out.
"Let me see, your mother missed it in the morning after I came to Tresco."
"That's three days ago." And I could hardly believe the boy. It seemed to me that months had passed. But he was right.
"Yes, three days ago. Your mother missed it in the morning. It is likely, then, that it was taken from the lock of the door the night before."
"That would be the night," said Dick, suspiciously, "when you tapped on my window."
"The night, in fact, when I first landed on Tresco. Wait a little."
Dick sat still upon the grass, and I took the key from his hand into mine. There were many questions which at that moment perplexed me--that hideous experience in Cullen Mayle's bedroom, the rifling of Adam Mayle's grave, the replacing of the plan in it and the disappearance of the cross, and I was in that state of mind when everything new and at all strange presented itself as a possible clue to the mystery. It seemed to me that the key which I held was very much more than a mere rusty iron key of a door that was never locked. I felt that it was the key to the door of the mystery which baffled me, and that feeling increased in me into a solid conviction as I held it in my hand. I seemed to see the door opening, and opening very slowly. The chamber beyond the door was dark, but my eyes would grow accustomed to the darkness if only I did not turn them aside. As it was, even now I began to see dim, shadowy things which, uncomprehended though they were, struck something of a thrill into my blood, and something of a chill, too.