The Doctor shrugged his shoulders, but he listened to me patiently. He did not believe a word of the story, that was clear; but he heard it all from beginning to end. “My dear fellow,” he said, “the boy told me just the same. It’s an epidemic. When one person falls a victim to this sort of thing, it’s as safe as can be,--there’s always two or three.” “Then how do you account for it?” I said. “Oh, account for it!--that’s a different matter; there’s no accounting for the freaks our brains are subject to. If it’s delusion, if it’s some trick of the echoes or the winds,--some phonetic disturbance or other--” “Come with me to-night, and judge for yourself,” I said. Upon this he laughed aloud, then said, “That’s not such a bad idea; but it would ruin me forever if it were known that John Simson was ghost-hunting.” “There it is,” said I; “you dart down on us who are unlearned with your phonetic disturbances, but you daren’t examine what the thing really is for fear of being laughed at. That’s science!” “It’s not science,--it’s common-sense,” said the Doctor. “The thing has delusion on the front of it. It is encouraging an unwholesome tendency even to examine. What good could come of it? Even if I am convinced, I shouldn’t believe.” “I should have said so yesterday; and I don’t want you to be convinced or to believe,” said I. “If you prove it to be a delusion, I shall be very much obliged to you for one. Come; somebody must go with me.” “You are cool,” said the Doctor. “You’ve disabled this poor fellow of yours, and made him--on that point--a lunatic for life; and now you want to disable me. But, for once, I’ll do it. To save appearance, if you’ll give me a bed, I’ll come over after my last rounds.”