“I cannot,” said Minna, “it seems to me absolutely unexplainable. For generations those pearls have descended from parent to child,—sometimes a mother owned them, sometimes a father, but they were always given to the oldest daughter, or, if there were no daughter, then to a son. Only in case of a childless inheritor did they go to a niece or nephew. Why my husband should so definitely bequeath them to his niece,—I cannot imagine. I’ve thought over that for hours, but I can’t understand it I will say frankly, that Betty and her father frequently had differences of opinion, but nothing more than many families have. They were really devoted to one another, but both were of decided, even obstinate nature, and when they disagreed they were apt to argue the matter out, and as a result of it, they did sometimes lose their temper and really quarreled. But it always blew over quickly and they were good friends again. I never paid any attention to their little squabbles, for I knew them both too well to think they were really at enmity. But this matter of the pearls looks as if my husband had a positive dislike for the child, and as a mark of spite or punishment left the pearls away from her. It makes little difference, if—if——” “Don’t think about that, Mrs Varian,” said Wise, kindly; “I’m considering this strange clause of Mr Varian’s will from the viewpoint of the whole mystery. It may prove a clue, you see. I want to say, right now, that the whole affair is the greatest and most baffling puzzle I have ever known of. The disappearance of your daughter and the death of your husband offer no solution that seems to me possible,—let alone probable. I can set up no theory that does not include a secret passage of some sort. And though I am emphatically informed there is none, yet, as you may imagine, I must investigate that for myself.” “I’ve found the house plans,” said a low, thin little voice, and the strange girl, Zizi, appeared in the room. That slender little wisp of humanity had an uncanny way of being present and absent, suddenly, and without explanation. She was there, and then she wasn’t there,—but her goings and comings were so noiseless and unobtrusive that they were never noticed. Pennington Wise held out his hand without a word. Zizi gave over a bulky roll of papers and subsided. Unrolling the time-yellowed sheets, they saw that they really were the old contractor’s plans of the house. With a sigh of satisfaction Wise commenced to study them,—Granniss looking over his shoulder. Minna sat quietly, her nervousness lost in her eager anticipation of the new detective’s successful quest. The two men studied the plans carefully. “I wish North could see these,” Rodney said; “he’s of an architectural bent, Mr Wise, and he measured the house all over, trying to find an unexplained bit of space. According to these plans, North is right, and there isn’t any.”