After they had crossed the barbed wire the woods suddenly closed about them as though a door had been softly shut behind them.

The ground now squelched beneath their feet, the sky between the trees was like damp blotting-paper, and the smell that had been only faintly in the air before was now heavy around them, blown in thick gusts as the wind moved through the trees.

Shrapnel now could be distinctly heard at no great distance, with its hiss, its snap of sound, and sometimes rifle-shots like the crack of a ball on a cricket bat broke through the thickets.

They separated, spreading like beaters in a long line: "Soon," Trenchard told me, "I was quite alone.

I could hear sometimes the breaking of a twig or a stumbling footfall but I might have been alone at the end of the world.