The secrets of the tunnel are not the author’s at first hand; he did not personally experience its dank embrace; he did not “labour and pray” in its recesses with a sense of intimate proprietorship. In fact, except for some organising assistance on the actual night of the escape, he had nothing actively to do with it. The control of the enterprise rested in the hands of a select few who were known as the “working-party” and on whom devolved the whole responsibility of doing the job and seeing that it was done in secret. It was impossible for those whose business it was to keep in close personal touch with the whole community to remain long in ignorance of the identity of the various members of this party. But what they were doing, how or exactly where they were doing it, when they would finish doing it—on these points one was not, and did not expect to be, enlightened. When the working-party discussed plans, they did so behind closed doors and in an undertone. The results of their deliberations were communicated to those whom it concerned and to those alone. Once the shifts had been arranged there was no need for a member of the party to do more than be in his appointed place at the appointed time and carry out his appointed task. In the intervals the less he talked the better. It was only when the scheme was nearing its maturity and when it became desirable to let a favoured few into the secret that tongues began ever so circumspectly to wag. When the essay became an event, and the tunnel the one topic of conversation through the camp—and, be it said, through Hanover as well—it was possible to join the odd ends together and follow the whole enterprise through in the retrospect from its modest beginning to its glorious conclusion. This is all that this account pretends to do. * * * * * At this juncture it may be well to describe the premises. [Illustration: General plan of Holzminden Camp (Scale approx. 1 inch = 50 yards) ]