Peter nodded. The Heynal was not new to him, and he knew that the boy was playing as usual—that is, he knew up to a certain point. Joseph hesitated at the place where the music ordinarily breaks off—this time he added three notes of his own which definitely finished the Heynal. It took courage to play those notes, for he knew not but that at any moment he might feel the Cossack’s dagger in his throat. At length he let the trumpet fall and looked about. The blood surged into his head with a rush. The Cossack was nodding approval! He did not know, then! He went to the windows at south, east, and north, successively, and played as he had already played. “Now hurry for your lodgings!” Peter gripped the boy’s arm and pushed him ahead all the way down the stairs, after giving final orders to the men who guarded Pan Andrew. They found no one in the square below and slunk along in the shadows toward the university district. The Cossack was exulting again that his plans were working, and as he went along he looked about him for a quiet corner where he could finish Joseph with his dagger once he had the crystal in his hands and was on the way back to the tower. Then they would settle with the father and there would be no one left to give information concerning them. A company of Armenian merchants would leave the city unhindered in the course of the following day. CHAPTER XII ELZBIETKA MISSES THE BROKEN NOTE Very much earlier on this same eventful night a girlish figure emerged from the door leading to Alchemist Kreutz’s lodgings on the third floor of the building where Pan Andrew lived, and stole quietly down the steps to the second floor. Here she rapped three times. In a space of perhaps a minute, the door was thrown back a little, and Joseph’s mother peered cautiously out through the crack. “Come in, child,” she said heartily as she recognized Elzbietka’s face. “What brings you out so late?” she inquired a moment later as she shot the heavy bolts back into place and secured the door. “Has the student Tring been troubling you or your uncle lately, or what is it? Sit there at the table where I was just finishing my sewing for the day and tell me the whole story.” “Yes,” answered the girl, “it is the student Tring. He and uncle are in the loft now, and I am somewhat frightened—they have been talking more queerly than ever all this evening.” “You must stay with me here this night,” the woman said. “It’s a shame that such a scholar as your uncle should have anything to do with that student, Tring. I fear that young man very much. He seems to me like one who has grown old and then become young again. When he looks at me with those great dark eyes it seems as if he were thinking of terrible things——”