"Humph! I don't know so much about that," said Naball disbelievingly. "What nonsense," broke in Ezra angrily; "she could not have done such a thing--she had no motive." Naball did not reply to this remark, but rising from his seat, walked hurriedly up and down the room in a state of great excitement. He had been fully convinced of the guilt of Stewart, but the conversation of Eugénie had shaken his belief, and he began to puzzle over the new aspect of the case. "I wonder if Caprice ever had any dealings with Lazarus?" he said to himself, thinking of the diamond robbery. "Yes," broke in Eugénie sharply, "she had--at least," in answer to Naball's questioning look, "when I was at the theatre on Saturday night a boy near me said he had seen her at Lazarus's place." "A boy," asked Ezra sharply, "what boy?" "I don't know," she replied; "a thin, pale-faced Jewish-looking boy, with a shrill voice." "Isaiah," said Naball and Ezra with one voice, and then looked at one another, amazed at this new discovery. "By Jove!" said the detective, "this is becoming exciting. You are sure you heard the boy say that?" "Yes, I'm sure--quite sure," answered Eugénie firmly; "but I don't think that could prove Caprice guilty. Much as I wish to serve Keith, I don't want to ruin her." Naball glanced at her keenly, then turned to Ezra. "Send for the boy," he said sharply, "and we'll find out all about Caprice's visits to your father's place." "It mightn't have anything to do with the murder," said Ezra, ringing the bell for the messenger. "True," replied Naball, "but, on the other hand, it might have a good deal to do with the diamond robbery." CHAPTER XXIII. THE CYPHER. When the messenger had been despatched, Naball drew his seat up to the table, and began to make some notes, after which he turned to Eugénie. "I was firmly convinced of Stewart's guilt," he said quietly; "but what you have told me throws a new light on the subject. I said you could not do that--I beg your pardon--you can." Eugénie bowed her head in acknowledgment of the apology, and asked him a question in a hesitating manner. "You don't think Caprice is guilty?" "I think nothing at present," he replied evasively; "not even that Stewart is innocent. When I see the boy, I'll tell you what I think." They talked on together for a few minutes, and then there came a knock at the door. In reply to Ezra's permission to enter, the door opened, and Isaiah appeared on the threshold, holding some papers in his hand. "Oh, you've come," said Ezra, as the boy shut the door after him. "Yes; did you want me?" demanded Isaiah in a jerky manner, "'cos I never knowed you did." "Didn't you meet a messenger?" asked Naball, turning his head round. Isaiah deposited the papers he carried on Ezra's desk, and shook his head. "No, I never met any one, I didn't," he answered. "Mr. Ezra asked me to bring all letters that came to the old 'un, so as these came, I did."