Peter had struck the billets and repairing shop of a squad of German sappers.
He was just going ruefully to retrace his steps and try to find a good place to swim the stream when it struck him that the officer who had passed him wore clothes very like his own.

He, too, had had a grey sweater and a Balaclava helmet, for even a German officer ceases to be dressy on a mid-winter's night in Anatolia.

The idea came to Peter to walk boldly across the bridge and trust to the sentry not seeing the difference.
He slipped round a corner of the hut and marched down the road.

The sentry was now at the far end, which was lucky, for if the worst came to the worst he could throttle him.

Peter, mimicking the stiff German walk, swung past him, his head down as if to protect him from the wind.
The man saluted.