"I've got to use most of the money," answered the boy, and left the window. A hundred and fifty dollars was quite a sum, even for Robert to handle, and he placed the amount in the breast pocket of his coat. The flashily-dressed man saw the youth stow the bank bills away, and his eyes glistened greedily. He was a sharper by the name of Andy Cross, and it is doubtful if he had ever done an honest day's work in his life. The money order he carried was one belonging to a man who had been stopping at the same boarding place at which Andy Cross had put up. The order had come in a letter the day before, and Cross was anxious to get it cashed before Charles Shotmore should become aware of his loss. "I've a good mind to follow that boy and see if I can't get hold of that money," said Cross to himself. As Robert went out of the post-office he came behind him. Not far away was a drug store, where several directories lay on a stand for the use of the public. Robert stepped into the drug store to look for Herman Wenrich's name in the directory, and Andy Cross took a stand outside where he might watch the boy. While the sharper was waiting, he felt himself touched on the arm, and wheeling about, found himself confronted by the man to whom the stolen money order belonged. "Mr. Smith, I wish to speak to you," said Charles Shotmore, somewhat excitedly. He did not know Cross' real name, for he had never heard it. "What do you want?" demanded Andy Cross, as coolly as he could, although he was much disconcerted. "I--I--that is, I believe you have a letter belonging to me." "A letter belonging to you?" "Yes." "I have no such letter, Mr. Shotmore. What makes you think I have?" "The servant at the boarding house says a letter came yesterday for me, and that she saw you pick it up from the hall rack." "She is mistaken." "She says she is positive, and--and she says your record is none of the best." "Sir, do you mean to insult me!" demanded Cross, but his face turned pale with sudden fear. "The girl comes from the South End, and she says you are known by the name of Cross. She is positive you took my letter, and I want it." "Preposterous! Why should I take your letter?" "I don't know. But I was expecting a money order from my aunt, and if it was in the letter I want it." "Did you follow me to here?" asked Andy Cross, nervously. "I came down to the post-office, yes, for that is where they cash money orders." "Well, I haven't your money order, and that is all there is to it. Let go of my arm." For Charles Shotmore had clutched the sharper while they were conversing. At that moment Robert came out of the drug store. On catching sight of Cross in the grasp of another, he paused in wonder. "Something is wrong," he thought, and drew closer to the pair. "I am of the opinion that you have the money order," said Charles Shotmore. "If you are an honest man you will not object to being searched."