“How is that to be done?” asked De Gayangos gloomily. “I have been doing my best at Pierside, but I cannot find a single clue. Vasa is not to be found.”

“Vasa!” exclaimed Archie and the Professor, both profoundly astonished.

Don Pedro raised his eyebrows.

“Certainly. Vasa, if anyone, must have killed your assistant, since he alone could have known that the jewels were buried with Inca Caxas.”

“But, my dear sir,” argued Hope good-naturedly, “if Vasa stole the manuscript, whether translated or not, he certainly must have learned the truth long, long ago, since thirty years have elapsed. In that event he must have stolen the jewels, as Professor Braddock remarked lately, before he sold the mummy to the Parisian collector.”

“That may be so,” said Don Pedro obstinately, while the Professor muttered his approval, “but we cannot be certain on that point. No one—I agree with the Professor in this—would have risked his neck to steal a mere mummy, therefore the motive for the committal of the crime must have been the emeralds. Only Vasa knew of their existence outside myself and my dead father. He, therefore, must be the assassin. I shall hunt for him, and, when I find him, I shall have him arrested.”

“But you can't possibly recognize the man after thirty years?” argued Braddock disbelievingly.

“I have a royal memory for faces,” said Don Pedro imperturbably, “and in the past I saw much of Vasa. He was then a young sailor of twenty.”

“Humph!” muttered Braddock. “He is now fifty, and must have changed in thirty years. You'll never recognize him.”

“Oh, I think so,” said the Peruvian smoothly. “His eyes were peculiarly blue and full of light. Also, he had a scar on the right temple from a blow which he received in a street riot in which I also was concerned. Finally, gentlemen, Vasa loved a peon girl on my father's estate, and she induced him to have the sun encircled by a serpent—a Peruvian symbol—tattooed on his left wrist. With all these marks, and with my memory for faces, which never yet has failed me, I have no doubt but what I shall recognize the man.”