The uncommercial transaction which had brought me and Jack together, was this:—I had entered the Liverpool police force, that I might have a look at the various unlawful traps which are every night set for Jack. As my term of service in that distinguished corps was short, and as my personal bias in the capacity of one of its members has ceased, no suspicion will attach to my evidence that it is an admirable force. Besides that it is composed, without favour, of the best men that can be picked, it is directed by an unusual intelligence. Its organisation against Fires, I take to be much better than the metropolitan system, and in all respects it tempers its remarkable vigilance with a still more remarkable discretion. Jack had knocked off work in the docks some hours, and I had taken, for purposes of identification, a photograph-likeness of a thief, in the portrait-room at our head police office (on the whole, he seemed rather complimented by the proceeding), and I had been on police parade, and the small hand of the clock was moving on to ten, when I took up my lantern to follow Mr. Superintendent to the traps that were set for Jack. In Mr. Superintendent I saw, as anybody might, a tall, well-looking, well-set-up man of a soldierly bearing, with a cavalry air, a good chest, and a resolute but not by any means ungentle face. He carried in his hand a plain black walking-stick of hard wood; and whenever and wherever, at any after-time of the night, he struck it on the pavement with a ringing sound, it instantly produced a whistle out of the darkness, and a policeman. To this remarkable stick, I refer an air of mystery and magic which pervaded the whole of my perquisition among the traps that were set for Jack. We began by diving into the obscurest streets and lanes of the port. Suddenly pausing in a flow of cheerful discourse, before a dead wall, apparently some ten miles long, Mr. Superintendent struck upon the ground, and the wall opened and shot out, with military salute of hand to temple, two policemen—not in the least surprised themselves, not in the least surprising Mr. Superintendent. ‘All right, Sharpeye?’ ‘All right, sir.’ ‘All right, Trampfoot?’ ‘All right, sir.’ ‘Is Quickear there?’ ‘Here am I, sir.’ ‘Come with us.’ ‘Yes, sir.’ So, Sharpeye went before, and Mr. Superintendent and I went next, and Trampfoot and Quickear marched as rear-guard. Sharp-eye, I soon had occasion to remark, had a skilful and quite professional way of opening doors—touched latches delicately, as if they were keys of musical instruments—opened every door he touched, as if he were perfectly confident that there was stolen property behind it—instantly insinuated himself, to prevent its being shut.