Deep under the Yorkshire moors a network of tunnels houses the equivalent of a small town. Who built it and when? What is its purpose? It wasn't until George's sudden death that anyone ever questioned life at The Camp. Life wasn't perfect, of course – in these times, what was? There was always organising to do, and the work never stopped, but something had changed. And for three friends, a sense of curiosity would turn into an alarming sense that something had gone wrong, and an urgent need to escape. But escape to where? And how?