"We will go downstairs," I said.

We returned to Sir Henry's library. It was my turn now to lock the door.

"Why do you do that?" he asked.

"Because I wish to be quite certain that no one overhears our conversation."

"What have you got to say?"

"I have a plan to propose to you."

"What is it?"

"I want you to change bedrooms with me to-night."

"What can you mean?—what will Lady Studley say?"

"Lady Studley must know nothing whatever about the arrangement. I think it very likely that the apparition which troubles you will be discovered to have a material foundation. In short, I am determined to get to the bottom of this horror. You have seen it often, and your nerves are much shattered. I have never seen it, and my nerves are, I think, in tolerable order. If I sleep in your room to-night—"