We reached the naked abutment, and drew ourselves forward on our faces in the shadow of its rails till we could nearly touch the grey skeleton of underhung girders, and see the single sentry leaning against the other abutment, sixty yards across the gulf. Whilst we watched, he began to move slowly up and down, up and down, before his fire, without ever setting foot on the dizzy bridge. I lay staring at him fascinated, as if planless and helpless, while Fahad shuffled back by the abutment wall where it sprang clear of the hillside.

This was no good, for I wanted to attack the girders themselves; so I crept away to bring the gelatine bearers. Before I reached them there was the loud clatter of a dropped rifle and a scrambling fall from up the bank. The sentry started and stared up at the noise. He saw, high up, in the zone of light with which the rising moon slowly made beautiful the gorge, the machine-gunners climbing down to a new position in the receding shadow. He challenged loudly, then lifted his rifle and fired, while yelling the guard out.