“I am half dead with fear,” she said. “Who could it have been?”

“We will try to guess tomorrow,” I replied. “In the meantime say nothing to anyone of what we have heard and seen.”

“Why not?”

“Because silence is safe, and we have need of safety in this house.”

I sent Laura upstairs immediately, waited a minute to take off my hat and put my hair smooth, and then went at once to make my first investigations in the library, on pretence of searching for a book.