And the assumed Mr. Maxwell, in whom no one, not even, we venture to say, Caleb Hook himself, had he not been in the secret, would have recognized our young friend, Frank Mansfield, resumed his seat at the desk behind the glass partition, and began figuring away upon a large book of accounts. Yes, it was Frank Mansfield. Detective Hook's plan had succeeded to the letter. For two weeks he had been an inmate of the business office of the man who had plotted his ruin. And during that short lapse of time many things had occurred. Let us narrate them briefly, as they are highly essential to a correct understanding of subsequent events. In the first place, the matter of the Webster bank robbery remains still a mystery. It is generally believed that Frank Mansfield was at least a participant in the crime, a guilty tool of the thieves. From the moment of his escape from Officer Schneider, the whereabouts of that young gentleman have been a matter of mystery to the world. When, through the accident which had happened to Detective Hook, the burglar Joe Dutton had been captured with his basket of stolen dollars at the Catherine Market, it had been thought by the police authorities that a speedy solution of the mystery was at hand. They were mistaken. During the four days of his confinement in the Tombs the captured criminal could not be persuaded to utter a word. On the morning of the fifth day burglar Joe Dutton was found lying dead upon the floor of his cell. Upon the same day occurred the funeral of the murdered Mrs. Marley. Through some unknown source a lot had been purchased in a suburban cemetery. Detective Hook and Frank Mansfield, concealed within a closed carriage, were the sole mourners who followed to the grave. Not the slightest clew to the perpetrator of this cowardly murder had been obtained by the police, but then they had not exerted themselves very violently, you see. Mrs. Marley was only a poor, half crazy woman--there was no money in the case. But in the busy rush of New York already were these matters well-nigh forgotten. The robbery of the Webster bank, the disappearance of Frank Mansfield, and the murder of Mrs. Marley were all things of the past. Maxwell, the clerk, had been engaged at his books not over an hour--and even that short space of time had sufficed to bring the short winter's day nearly to a close--when the office door again opened and a flashily dressed young man smoking a long cigar entered. "Callister about?" he asked, with an air of general proprietorship of the whole establishment. Mr. Maxwell peeped through the little round opening in the glass partition and immediately opened the door. "He's in, but very busy," he replied, stepping into the outer room. "Tell him Detective Cutts wants to see him, will you, young feller?" said the individual with the cigar.