"Absolutely sure, your Grace," I answered.
He turned away from me.
"In my own house, under my own roof," I heard him mutter. "Good God!"
I had scarcely believed him capable of so much feeling. When he resumed his seat and former attitude I could see that his face was almost gray.
"This is terrible news," he said. "I am not at all sure, though, Mr.
Ducaine, that any blame can attach itself to you."
"Your Grace," I answered, "there were three men only who knew the secret of that combination. One is yourself, another Colonel Ray, the third myself. I set the lock last night. I opened it this morning. I ask you, in the name of common sense, upon whom the blame is likely to fall? If I remain this will happen again. I cannot escape suspicion. It is not reasonable."
"The word was a common one," the Duke said half to himself. "Some one may have guessed it."
"Your Grace," I said, "is it likely that any one would admit the possibility of such a thing?"
"It may have been overheard."
"It has never been spoken," I reminded him. "It was written down, glanced at by all of us, and destroyed."