“I know—­I know!” admitted Fullaway with a groan.  “I’m frightfully careless—­always was.  I quite admit it, Mrs. Marlow, quite!”

“Of course,” continued Mrs. Marlow, in precise, even tones, “of course if you left the letter-book lying round, and the book in which the duplicates of all our telegrams and cablegrams are kept, too—­why, this Ebers man could easily read what he liked for himself when he was in here of a morning before you got up.  He was in and out a great deal, that’s certain.  And as regards those two affairs, the documents we have about them are pretty plain, Mr. Fullaway.  Anybody of average intelligence could find out in ten minutes from our letter-book and telegram-book that we negotiated the sale of the Pinkie Pell pearls to Miss Lennard, and that Mr. James Allerdyke was bringing here a valuable parcel of jewels from Russia.  And,” concluded Mrs. Marlow quietly, “from what I saw of him, Ebers was a smart man.”

Van Koon, who had been listening attentively to all this, turned a half-whimsical, half-reproving glance on Fullaway, who sat in a contrite attitude, drumming his fingers on the polished table.

“I guess you’re a very careless individual, my friend,” he said, shaking his head.  “If you will leave your important papers lying about, as this lady says you’re in the habit of doing, what do you expect?  Now, you’ve been wondering who got wind of this jewel deal, and here’s the very proof that you gave every chance to this Ebers to acquaint himself with it!  And what I’d like to know now, Fullaway, is this—­what use do you suppose this young fellow made of the information he acquired?  That seems to me to be the point.”

“Yes!” exclaimed Allerdyke suddenly.  “That is the point!”

Fullaway smote the table.

“The thing’s obvious!” he cried.  “He sold his information to a gang.  There must have been—­I mean must be—­a gang.  It’s utterly impossible that all this could have been worked by one man.  The man we’ve heard of in connection with the deaths of Lisette Beaurepaire and of Ebers himself is only one of the combination.  I’m as sure of that as I am that I see you.  But—­who are they?”

Nobody answered this question.  Allerdyke plunged his hands in his pockets and stared at Fullaway; Mrs. Marlow began to trace imaginary patterns on the surface of the table; Van Koon produced a penknife and began to scrape the edges of his filbert nails with a preoccupied air.

“There’s the thing I’ve insisted on all along, Fullaway, you know,” he said at last, finding that no one seemed inclined to speak.  “I’ve insisted on it, but you’ve always put it off.  I don’t care what you say—­it’ll have to come to it.  Let me suggest it, now, to our friends here—­they’re both cute enough, I reckon!”

“Oh, as you please, as you please!” replied Fullaway, with a wave of his hands.  “Say anything you like, Van Koon—­it seems as if too much couldn’t be said at this juncture.”