As The Shells Whistle.
Part 1:

He sits, muddied and sick, back against the slick, clay side of the trench. He watches as stretcher bearers carry the wounded away, back from the line, behind the guns, far back to the hospitals, with the pretty nurses. Away from the hellish choir of rifles and machineguns, to places where even the dull rumble of heavy artillery ceases to exist. He watches as the men are taken away, swathed in hasty, coarse field bandages, blood seeping through and trickling across an arm here, a bare chest there. The thick, red blood, gushing from a gaping stomach wound, or a shell amputated limb, encrusted with the treacly black mud that clots everything, breathing, eating. That gets into every crevice and space, into every cup of over strong tea. He flinches as an incoming shell lands close by, splinters of metal slap into the rotting sandbags above him. Another shell whistles in, the sharp whine cutting through the constant stutter of rifles, the explosion sending mud cascading over him, over another pair of stretcher bearers and their charge. A blinded man, an arm and leg torn off by shells, shrapnel tearing his eyes and face away into oblivion. Mercifully unconscious, hopefully never to wake again. He sighs as a machinegun chatters to life in the next bay. He sighs as he surveys the mass of troops around him, nervously tense. Ready, but unwilling to face what the next few minutes might hold for them. He pats the wooden ladder next to him, the ladder he would soon have to charge up, out of the relative safety of the trench. Soon he would have to face the maelstrom of hot lead, the deadly hail of impersonal hatred. Even though he did not adhere to any faith, he still crossed himself as a priest concluded a prayer for their victory and safety. The shells continued to whistle overhead, continuing to explode in the middle of no-mans-land, probing, seeking, wanting the extinction of human life. He cautiously peers over the lip of the trench, taking in the barbed wire, mile after mile of rusted wire, rent and torn from shell after shell, repaired nightly. The huge craters, like a landscape brought back from the moon, and placed here. Placed here, on them, around them, for them, to fight and kill other, anonymous young men, who were intent, and more than willing, to kill you, so they themselves could continue breathing for another day. He slumps back into the bottom of the trench before a sniper can spot him. Only yesterday, his platoon commander had been killed by a sniper, along with two others. One of the platoon had spotted the muzzle flash. Seeing the inert body of a man falling from a tree had been a satisfying sight. He woke up to the present as a salvo of shells straddled the trench. The force of the explosion deafens him and the other occupants of the trench. Part of the trench wall collapses in, half covering another man. He watches as others dig him out. He feels something running down his cheeks, and over his upper lip. He can still hear nothing except a loud ringing in his ears. He drags his hand under his nose. It comes away red and sticky with blood. The same with both ears. The concussion from the nearby explosions has burst his eardrums. He sees others readying, moving up to the ladders, sees an officer, face red and cords in his neck as he shouts orders. He cannot hear a thing. Except the continuous ringing and buzzing. He picks up his rifle from where it leans against the trench wall. He moves to the ladder. He watches the man next to him. The man next to him tenses, then catapults himself out of the trench, headed for the nearest shell hole, and relative safety. He doesn’t make two feet. His chest explodes in a red fountain as a machinegun bursts into life, somewhere ahead. The body topples back onto the next man coming up. He feels a hand shoving him in the back, pushing him up the ladder. He resists for a second, unwilling to face certain death, then goes. Over the top, almost diving, low, into the nearest shell hole. At the bottom, one of his platoon, blood sluggishly crawling from a neat hole drilled into his forehead. He quickly steals his ammunition, grenades and water, then sprints to the next shell hole. A deep pool of thin, watery mud splashes up and clings to his uniform as he slides down the slope. Two others look at him as he crawls to join them. He sees one begin to speak, but he shakes his head, pointing to his ear. The others see the semi congealed blood, and one nods. One mimes out where machinegun positions are. He nods, points, then sprints through the mud, diving over a row of barbed wire and pickets. The other two sprint after him. The first retaliatory shells scream in. The two disappear in a flash of flame. When the smoke clears, both lie in the mud, mutilated beyond recognition. He looks back only once. Then forwards once more. Up ahead, the main body of the assault wave is stuck, trapped on a line of wire, and a savage cross fire. The second salvo of shells falls among them, decimating their numbers. And yet freeing them. A number of shells fall short, shattering the wire barrier in a few places. The trapped soldiers capitalise on this, rushing through the gaps, braving the redirected crossfire. He watches as more men run through, some being blown apart, others dancing jerkily to the tune of many guns. Another salvo screams out of the clear, blue sky, into the chaotic maelstrom of smoke, mud, noise, angry lead and struggling men. As it lands, he jumps up and runs. Through shell hole after shell hole, ducking, weaving, using as much cover as possible. Stray pieces of wire catch at him as he runs, tearing his uniform, scratching at his skin. He runs, boots heavy with clinging mud, mud trying to hold him back, hold him for the bullets and falling shells, holding him after that for the fat, sleek, corpse eating rats. The front soldiers are only a few dozen metres ahead. He dodges through a gap in the wire, escaping the rifles and machineguns. He catches the stragglers of the front line. A flash of light, and he stumbles, an enormous stinging pain making his legs buckle. A darkness blinds him as he staggers on. A fire burns in his side, and something warm and wet slides down his forehead, into his eyes. Then a sharp shock in his stomach, a violent punch in his abdomen. He stumbles on, feet tripping over corpses, discarded rifles. A second red hot poker, tearing into his stomach. He falls to his knees as a shell explodes behind him.