“No?” says Mr. Guppy, greedily curious. “What’s the story, miss? Is it anything about a picture?”

“Pray tell us the story,” says Watt in a half whisper.

“I don’t know it, sir.” Rosa is shyer than ever.

“It is not related to visitors; it is almost forgotten,” says the housekeeper, advancing. “It has never been more than a family anecdote.”

“You’ll excuse my asking again if it has anything to do with a picture, ma’am,” observes Mr. Guppy, “because I do assure you that the more I think of that picture the better I know it, without knowing how I know it!”