This is the first time I am ever trying to post for a competition, so I hope I got everything right.
Killing the sick.
Two young twins were sitting in a classroom. They had the extremely rare pariah gene and once it was discovered the Inquisition immediately took interest in them. They were physically fit for service and they would make a great asset to the Ordo Hereticus in their witch hunting duties. The only inconvenience was, that they actually refused to serve the Inquisition. They were very stubborn and not even threats could convince them otherwise. While some puritans wanted to execute them for impiety, a radical Inquisitor took charge of them. To his mind it would be an extreme waste to kill them. He wanted to understand, why they did not want to serve. Obviously they were no cowards. When he asked them, they answered with contempt, saying that the Inquisition kills thousands of innocents every day. The inquisitor smiled at their naivety and said "No one really is innocent in this Universe. Even the purest can be corrupted. Let me tell you a story."
Huskin was a farmer at some poorly developed agri-world. The tithes were high and he had to work hard to feed his family, but he did not complain. He went to church everyday and prayed to the Emperor. He never asked anything from Him. He always prayed to praise Him. He praised him for giving him his beloved wife, he praised him for beautiful moon revolving around his world, he praised him for his protection and so on. He hardly had to confess to any sins. Even when the crops were bad, he still did not lose his eternal optimism and his faith in the Emperor's protection and benevolence.
However that changed on the day, when his wife got terribly sick. The town's healer told Huskin, that she would probably die. He was desperate. He pleaded the good doctor to save her, he said he would do anything. Seeing Huskin so desperate the doctor found a victim. He showed him some ancient book. When he saw the first several pages Huskin recognised, that something was terribly wrong with it. He knew it was some sort of terrible witchcraft. "It is either that, or your wife dies." said the doctor to the farmer. So Huskin agreed to cure his wife using witchcraft. The ingredients for her cure were disgusting, but the cure had almost immediate effect. She got on her feet the day after. However it was at a horrible cost. She mutated. No one could really see it at the first sight. There were only hints. Bugs were coming into Huskin's house and it was more and more difficult getting rid of them. Then the flies came. They were somehow attracted by Huskin's wife. She ate less and yet became very fat. When she came to see the doctor, he was fascinated by the results, but reassured her, that this was a usual body reaction after the treatment he gave her.
She was horribly mutating and had to hide from people. Huskin was trying to put more pressure on the doctor, but instead of trying to help, he was just keen on studying his wife. That is when he realised that she has been part of a horrible experiment. Not even an experiment: a ritual. He threatened the doctor to denounce him, but the doctor just laughed at him. He knew Huskin would not do that for fear of his family being accused of consorting with dark powers. That was a great mistake. At this point things could have still been stopped quickly.
His wife left him. She feared to spread her contagion to his whole family. Wherever she went, death and plague followed. At first she was horrified with it, but she soon began to like it. She chose the path of damnation. Those wicked souls who follow Nurgle, believe that decay is the most natural state. They enjoy seeing it around them and yet they fear it. They are driven by the will of mastering it. They want immortality so they pay the price for it whatever their twisted god asks. That was hers case. She began to fear death, but enjoyed bringing misery and decay upon others. More people followed. Their cult was now so powerful, that not even the Arbites dared to cross it's path. More and more people, came to seek her 'blessings' for fear of their deaths or their loved one's. They did not realise, that once in Nurgle's power immortal life is a curse. When the governor finally recognised, that he could not contain the cult, he called for help. I was there. Just an acolyte like you following an Inquisitor's orders, but I was there. And I witnessed incredible horrors. People loosing painfully their legs in horrible mutations, while maggots were crawling out of them. People who in their madness were rubbing their faces with rat blood hoping to get some of the diseases, so that the plague god notices them. They all had to be burned in cleansing fire. But the worst was still to come. When we struck at the heart of the heretic's nest, we finally saw Huskin's wife. She and her cult were performing a great ritual, thanking their twisted god. They summoned little evil creatures called nurglings, who were eating rotted food from their tables. Some worshippers spread waters from sewers around the place to increase the horrible stench coming from their so called temple. Huskin's wife was no longer recognisable as human. She was nothing but a giant fat creature without teeth. Long grey, greasy hair covered all of her naked body. Her sweat and saliva were green. Whenever she coughed, people tried to approach her, hoping to receive more of Nurgle's blessings.
Emperor's justice had to be swift. We purged the whole place with holy fire and took her for interrogation. That is how I learned what happened on that world. So you may think of us Inquisitors as zealous fanatics and some of us are. Especially the puritans. But I belong among those, who are well aware of the fact, that we may be evil, but we are necessary evil. If we kill innocent lives, it is not because we enjoy it. It is because we try to save more of them. If we allow ourselves any compassion with the so called innocent people like Huskin, we endanger our whole species. Who gave us the right to take such difficult decisions? Well it is by the Emperor's mandate, that we protect humanity from the Warp.
The Emperor protects.