As the butler retired, Guildea shut the door rather cautiously. Father Murchison had never before seen him look so disturbed.

"You're worried, Guildea," the Father said. "Seriously worried."

"Yes, I am. This business is beginning to tell on me a good deal."

"Your belief in the presence of something here continues then?"

"Oh, dear, yes. There's no sort of doubt about the matter. The night I went across the road into the Park something got into the house, though what the devil it is I can't yet find out. But now, before we go down to dinner, I'll just tell you something about that proof I promised you. You remember?"

"Naturally."

"Can't you imagine what it might be."

Father Murchison moved his head to express a negative reply.

"Look about the room," said Guildea. "What do you see?"

The Father glanced round the room, slowly and carefully.