The House of Adventure by Warwick Deeping

So Brent went as a prisoner to Germany, and was catalogued as "Number 756941 Pte. Beckett, T. "; and Paul Brent's name appeared among the "missing," a casualty that was corrected a few weeks later to "killed."

Paul Brent was a prisoner, but he had escaped, escaped from the tradition of blond hair and a thin mouth, Turkey carpets and a three-tiered cake-stand, and the memory of the greedy nostrils of a thoroughly respectable but wholly unprincipled woman. He was free, even while he sat and peeled potatoes in a prison hut, washed his one shirt, or slept square-backed on his bed of boards. A sense of liberty soaked into him. He saw a new sun, a new horizon, new stars, a sportsman's chance, a renewal of the great adventure. His manhood tightened his belt, and discovered itself in better condition, despite its thirty-seven odd years and an incipient plumpness about the waist. That plumpness had disappeared in France and Belgium, and Brent's mental flabbiness followed it out of the German prison camp.