Van Vluyck rubbed her spectacles, adjusted them, and turned to Z; and a murmur of surprise when she said: “It isn’t here.”

“I suppose,” said Mrs. Plinth, “it’s not fit to be put in a book of reference.”

“Oh, nonsense!” exclaimed Mrs. Ballinger. “Try X.”

Miss Van Vluyck turned back through the volume, peering short-sightedly up and down the pages, till she came to a stop and remained motionless, like a dog on a point.

“Well, have you found it?” Mrs. Ballinger enquired after a considerable delay.

“Yes. I’ve found it,” said Miss Van Vluyck in a queer voice.

Mrs. Plinth hastily interposed: “I beg you won’t read it aloud if there’s anything offensive.”

Miss Van Vluyck, without answering, continued her silent scrutiny.

“Well, what is it?” exclaimed Laura Glyde excitedly.

“Do tell us!” urged Mrs. Leveret, feeling that she would have something awful to tell her sister.

Miss Van Vluyck pushed the volume aside and turned slowly toward the expectant group.

“It’s a river.”

“A river?”

“Yes: in Brazil. Isn’t that where she’s been living?”

“Who? Fanny Roby? Oh, but you must be mistaken. You’ve been reading the wrong thing,” Mrs. Ballinger exclaimed, leaning over her to seize the volume.

“It’s the only Xingu in the Encyclopaedia; and she has been living in Brazil,” Miss Van Vluyck persisted.

“Yes: her brother has a consulship there,” Mrs. Leveret interposed.

“But it’s too ridiculous! I—we—why we all remember studying Xingu last year—or the year before last,” Mrs. Ballinger stammered.

“I thought I did when you said so,” Laura Glyde avowed.

“I said so?” cried Mrs. Ballinger.

“Yes. You said it had crowded everything else out of your mind.”

“Well you said it had changed your whole life!”

“For that matter, Miss Van Vluyck said she had never grudged the time she’d given it.”

Mrs. Plinth interposed: “I made it clear that I knew nothing whatever of the original.”

Mrs. Ballinger broke off the dispute with a groan. “Oh, what does it all matter if she’s been making fools of us? I believe Miss Van Vluyck’s right—she was talking of the river all the while!”

“How could she? It’s too preposterous,” Miss Glyde exclaimed.

“Listen.” Miss Van Vluyck had repossessed herself of the Encyclopaedia, and restored her spectacles to a nose reddened by excitement. “ ‘The Xingu, one of the principal rivers of Brazil, rises on the plateau of Mato Grosso, and flows in a northerly direction for a length of no less than one thousand one hundred and eighteen miles, entering the Amazon near the mouth of the latter river. The upper course of the Xingu is auriferous and fed by numerous branches. Its source was first discovered in 1884 by the German explorer von den Steinen, after a difficult and dangerous expedition through a region inhabited by tribes still in the Stone Age of culture.’”

The ladies received this communication in a state of stupefied silence from which Mrs. Leveret was the first to rally. “She certainly did speak of its having branches.”

The word seemed to snap the last thread of their incredulity. “And of its great length,” gasped Mrs. Ballinger.

“She said it was awfully deep, and you couldn’t skip—you just had to wade through,” Miss Glyde added.

The idea worked its way more slowly through Mrs. Plinth’s compact resistances. “How could there be anything improper about a river?” she enquired.

“Improper?”

“Why, what she said about the source—that it was corrupt?”

“Not corrupt, but hard to get at,” Laura Glyde corrected. “Some one who’d been there had told her so. I daresay it was the explorer himself—doesn’t it say the expedition was dangerous?”

“ ‘Difficult and dangerous,’ ” read Miss Van Vluyck.

Mrs. Ballinger pressed her hands to her throbbing temples. “There’s nothing she said that wouldn’t apply to a river—to this river!” She swung about excitedly to the other members. “Why, do you remember her telling us that she hadn’t read ‘The Supreme Instant’ because she’d taken it on a boating party while she was staying with her brother, and some one had ’shied’ it overboard—‘shied’ of course was her own expression.”

The ladies breathlessly signified that the expression had not escaped them.

“Well—and then didn’t she tell Osric Dane that one of her books was simply saturated with Xingu? Of course it was, if one of Mrs. Roby’s rowdy friends had thrown it into the river!”

This surprising reconstruction of the scene in which they had just participated left the members of the Lunch Club inarticulate. At length, Mrs. Plinth, after visibly labouring with the problem, said in a heavy tone: “Osric Dane was taken in too.”

Mrs. Leveret took courage at this. “Perhaps that’s what Mrs. Roby did it for. She said Osric