As The Shells Whistle.
Part 2:

He watches the rat, watches it gnawing on a dismembered arm, half buried in the trench wall. He scratches in his arm pit as a louse comes to life, still watching the rat in sick fascination, as it slowly eats its way through the arm. He admires the sleek, fat body, thinking of the amount of fresh meat the rat would give if he could catch and kill it, and loathing it at the same time, knowing it would happily start eating him if he was suddenly killed. The louse continues to bite as he scratches at it. A sudden pop, and a small red stain appears under his arm as he squashes the insect. Behind him, he hears the bass rumble of the big field artillery as they fire another salvo of shells at the line of trenches in front of him. A few seconds later, he hears the whistle as the shells pass overhead. The trenches erupt in a spray of earth and fire as the shells explode, crushing, rending and incinerating men, foreigners in a foreign land, men like himself, fighting for survival in the hellish landscape around them. Full of death and destruction, wanton madness, murder, and amazing acts of bravery and stupidity. He stares at the rat hungrily, half starved and quite willing to kill and eat it. The whistle of incoming shells sounds loud in his ears and he involuntarily flinches as they explode behind his trench. The rat scurries away, fleeing to a safer position, disappearing until it was safe for it to come back out and resume its feast. He picks his rifle as more shells fall, short into no-mans-land. A distant whistle, and his trench comes alive with men lining the parapet, rifles at the ready. The machine gun starts up, sweeping across the bomb scarred landscape, streams of hot lead speeding across the earth, snuffing out the lives of many men who have come from the opposing trenches. He fires blindly, unable to make himself aim and deliberately kill someone. Better to simply pull the trigger and not know if it has an effect. Better to let the shells and bullets from other mens guns do the ungodly business of murder for him. He shoots, unknowing, uncaring if his bullets hit the approaching men or not. He watches, nauseated, as men become entangled in the rolls and fences of barbed wire, watches as they are shot, impaled and blown up as they struggle through the insidious mud. He suddenly feels pity for them, and begins to aim. The wounded, screaming men begin to drop as he calmly and methodically shoots them, silently giving the coupe de grace to dying men. The shells and guns finish many more before he can do so himself, leaving corpses and shattered bodies for the swarms of rats that would come out when all was over. He continues to shoot injured men, ending their agony. After awhile, he notices men getting closer, men now firing back, killing men around him. He thinks, all the shells, all the bullets, useless, these were not men, but men possessed by demons, their sole intention, the extinction of the men they were bearing down on. His pity evaporates, leaving a cold realisation. He would die today. These demon men would roll over them, trample them into the cold mud, leave them amongst the old bodies, the stench of putrefaction and the sleek, well fed rats. He begins to panic, his rifle shakes crazily in his hands, his careful, calm aim gone, replaced with wild jerky shots. He struggles to control himself. He sees a moment of hope. A last line of wire holds them back, trapping them, stopping them long enough for the artillery to gain on them, rending, tearing them, throwing away the pieces like discarded toys. Exorcising the demons, leaving hundreds of dead men. He laughs, a note of hysterical madness creeping in as he watches the purifying explosions of fire. He continues to reload and fire, laughing madly as the dance of death continues. The shells fall, blowing holes in the final wire barrier, allowing men to escape, to come closer, to continue their assault. He screams abuse at them, at the shells for releasing them. The men continue forward in the face of massed rifle and machinegun fire. He screams at them, hurling abuse and curses, to no real effect. He shoots anything he can see that moves. The men, and shells, march closer and closer. Right in front of him, twenty or so metres away, a shell lands next to a man. Bloodied, damaged, he continues to come. His heart stops. To see a man survive, and keep coming after such a close explosion, he believes is unnatural. He is convinced it is the Devil himself. Unnaturally calm, all his previous fears gone, he knows he faces the Devil. He reloads his rifle and aims. The first shot hits low in the stomach, and the man staggers, but continues. He really is the Devil, the man thinks. The second shot hits higher in the stomach, and the man collapses. The man pauses, elated, knowing he has killed the Devil. He screams his triumph and elation as a heavy shell lands in the trench at his feet.