(Kinda inspired by el despertar and warhammer 40K)
Hamelin was an idyllic town on a relatively unremarkable feudal world in the gothic sector.
Due to it's strategic insignificance the imperium rarely paid it any attention except for when collecting tithes, and for the most part the people lived their lives blissfully unaware of the horrors the galaxy at large had to offer.
But one day, a plague started to ravage the planet.
People in the hundreds began to fall ill to a mysterious disease no doctor could cure, their bodyparts blackened and fell off, boils in the shape of three circles appeared on their skin, and they eventually lost all sense of pain before death.
Those who were still in good health fled as far away as possible into another town, and after a few months the survivors felt that they could rejoice; not a single one of them caught the disease again.
And so the whole town celebrated with seven days of singing, drinking and dancing. Friends hugged each other in joy of having survived together, and children played outside completely fearless of encountering bloated bodies on the street.
Just a few weeks after that a horde of slavering undead appeared in front of the townsgate. Everyone did their best trying to stave off the monsters, but their efforts were in vain. Bodies already decayed and rotting ignored blades going through them and a thick coat of slime protected the undead from fire.
The mayor who kept himself and family locked in a fortress tried to call for help, but he knew that it could take months for the imperium to reach them.
When all hope seemed to be lost, a ship painted in garish colors arrived in front of the mayor’s house. A strange man dressed in blue robes decorated by feathers and peculiar curved symbols stepped out from it. In his hand he held an ornate golden flute.
He presented himself as the Pied Piper and told the mayor that he could solve their problem.
"But only if you pay me in nine chests of gold. As I see that your town is wealthy and prosperous, I know that you can afford me the payment."
Although highly suspecting that the man was a rogue psyker the mayor was desperate for a solution and so he and he piper shook hands.
The Piper went to the townsquare and began playing a hauntingly beautiful tune on his instrument, and soon hundreds of shambling corpses gathered around him. But instead of attacking they followed the strange musician until they reached a landfill.
There they began biting and clawing each other until only skeletons with scraps of flesh remained of the bodies.
”As you all can see I have fulfilled my part of the bargain. Now it’s your turn.”
The Piper bowed deeply in front of the mayor and smiled, but was met with a dour grimace.
”My city owe you our lives, and thus our eternal gratitude. However, to have any sort of dealings with your kind would sully our reputation forever. Now leave and be thankful that we will not report to the imperium of your heretical actions.”
The piper was completely silent for a long moment.
”I should have warned you that breaking our deal would have dire consequences for your people. But I have already foreseen that no argument will convince you to see the error of your choice, so I am not surprised.”
He then began playing another tune, this one had clashing and dissonant tones unlike the one before.
Pink, rotund creatures with arms asymmetrically arranged over their bodies appeared from the air, and tentacles the length of trees emerged from the grounf twisting and turning.
The mayor watched in horror as the warp abominations laid waste to his city.
”Just as planned.” Said the Piper and continued playing his flute.