One Good Turn by Chris Ryan

Chapter One
    The man hurt in his dream and he hurt when he woke.
    He was lying on a metal bed frame in a dark cellar. He was cuffed to it by the wrists and ankles. High up towards the ceiling, a cracked airbrick let in a little light so that he could see the bare walls, piles of rotting furniture and a wine rack along the far wall. The floor was puddled with water and the man could hear things running around in it.
    Something moved at the bottom of the bed. Before he could react, a weight moved up his leg and onto his chest. He lifted his head and saw a big, greasy rat squatting on him. He bellowed and threw himself from side to side. The rat flopped off onto the wet floor.
    He didn't go to sleep again. His head was splitting. The rats were everywhere and behind their grunting and scratching he could always hear the guns.
    Crump. Crump. Crumpcrumpcrumpump-mpmpmpumpcrump. Crump. Crump.
    That sound came from the big French guns down the line. You didn't just hear them. You felt them loosely in the gut.
    The war taught you to recognise the different guns.
    Eighteen-pound field guns went whizzzzz-BANG, depending on how close they were to the target. Once you heard the whizz, there wasn't much time till the bang. The German field guns sounded the same.
    Mortars, which lobbed bombs high in the air to land on an enemy's head, made three distinct noises. POUM as the round was launched, EEEEEEE as it flew through the air and CRACK as it landed.
    The big shells, the Pissing Jennies or Whistling Percies, screamed, then cracked the heavens open when they burst. They came from the heavy artillery as far as six miles behind the lines. A big gun might fire a sixty-pound shell but they were tiddlers compared to the big howitzers. These massive weapons slid along on special railways and fired 700-pound rounds.
    His personal nightmare was the enemy's Mil mortar – a huge brute that fired an 850-pound shell, practically the weight of a horse. The Ml 1 could blow a hole through four feet of reinforced concrete, or make a crater twenty-five feet deep. When you heard one of those screaming overhead, you knew men were going to die. Because the British Army thought concrete protection was cowardly and, anyway, you couldn't dig more than eight foot down into the Belgian mud without drowning.
    The sound of one shell bursting was bad. Two was enough to bring tears to your eyes. Bombardments could often last for hours – days even – with the shells bursting every few seconds.
    It was odd that he knew these things but did not know who he was. It was odd that the bed had no mattress and he was lying on its metal base. And it was odd that he was cuffed at the head and the feet so he could not move. In fact, everything was odd.
    He heard a scraping sound and turned his head.
    Christ, that hurt. His skin felt as if it had been scoured with sand and then dried until it cracked. His head was splitting. His jaw was loose. His tongue felt rough stumps where teeth should be. The entire length of his back felt raw. And the rawness went all the way down the backs of his legs. A distance away and above him, light flared as the cellar door opened.
    A figure appeared, a dark shape against the light, and footsteps sounded on creaky wooden stairs.
    'Mate. Mate,' he called out hoarsely. 'What's going on, mate?'
    The voice was cold and cruel. 'Don't "mate" me you horrid little man.' A face loomed over him, twisted with hate. "You're lucky you weren't shot on the spot."'
    The man watched as the figure turned, pulled a bottle of wine from a rack and left. The man on the bed started to cry. That was odd too. He cried himself back to sleep.
    He dreamed he was up to his neck in filthy water in a shell hole with sides of slippery clay. He was holding onto what he thought were tree roots, but when he looked again, he saw they were human limbs. The thirst was torturing him, but he couldn't drink because the water was a stew of rotting flesh and mud. He felt movement near him