When Frank arrived at the police office, he found a large crowd assembled; a young thief had just been brought in, charged with having abstracted a gentleman's pocket-book from his coat pocket, in Chatham Street. What was Frank's surprise at recognizing in the prisoner, the same boy who had been his companion in the Dark Vaults, on the proceeding night! The lad did not know Frank, for there was no similarity between the ragged, vagabond looking fellow of the night before, and the elegantly dressed young gentleman who now surveyed him with pity and interest depicted in his handsome countenance. It was a clear case--the young offender was seen in the act, and the pocket-book was found in his possession. The magistrate was about to make out his commitment, when Frank stepped forward, and required what amount of bail would be taken on the premises? 'I shall require surety to the amount of five hundred dollars, as the theft amounts to grand larceny,' replied the magistrate. 'I will bail him, then,' said Frank. 'Very well, Mr. Sydney,' observed the magistrate, who knew the young gentleman perfectly well, and highly respected him. 'You will wait here in the office for me, until I have transacted some business, and then accompany me to my residence,' said Frank--'I feel interested in you, and, if you are worthy of my confidence hereafter, your future welfare shall be promoted by me.' Frank had a long private interview with the magistrate. After having made arrangements for the capture of the two burglars, the young man urged the police functionary to take immediate measures for the breaking up of the band of desperate villains who lurked in the Dark Vaults, and the relief of the miserable wretches who found a loathsome refuge in that terrible place. The magistrate listened with attention and then said--