“Tell me first how the doctor managed to make a hole in the floor just in the nick of time.” “What! did you see the trap sprung?” “I saw everything.” “The devil you did! Had you any notion that signals were going on, all the while you were on the watch? We have a regular set of them in case of accidents. It’s a rule that father, and me, and the doctor are never to be in the workroom together--so as to keep one of us always at liberty to act on the signals.--Where are you going to?” “Only to get the gardener’s ladder to help us over the wall. Go on.” “The first signal is a private bell--that means, _Listen at the pipe._ The next is a call down the pipe for ‘Moses’--that means, _Danger! Lock the door._ ‘Stilton Cheese’ means, _Put the Mare to;_ and ‘Old Madeira’ _Stand by the trap._ The trap works in that locked-up room you never got into; and when our hands are on the machinery, we are awkward enough to have a little accident with the luncheon tray. ‘Quite Ready’ is the signal to lower the trap, which we do in the regular theater-fashion. We lowered the doctor smartly enough, as you saw, and got out by the back staircase. Father went in the gig, and I let them out and locked the gates after them. Now you know as much as I’ve got breath to tell you.” We scaled the wall easily by the help of the ladder. When we were down on the other side, Young File suggested that the safest course for us was to separate, and for each to take his own way. We shook hands and parted. He went southward, toward London, and I went westward, toward the sea-coast, with Doctor Dulcifer’s precious writing-desk safe under my arm. * The “Bow Street runners” of those days were the predecessors of the detective police of the present time. CHAPTER XII. FOR a couple of hours I walked on briskly, careless in what direction I went, so long as I kept my back turned on Barkingham. By the time I had put seven miles of ground, according to my calculations, between me and the red-brick house, I began to look upon the doctor’s writing-desk rather in the light of an incumbrance, and determined to examine it without further delay. Accordingly I picked up the first large stone I could find in the road, crossed a common, burst through a hedge, and came to a halt, on the other side, in a thick wood. Here, finding myself well screened from public view, I broke open the desk with the help of the stone, and began to look over the contents.