In ancient times, a certain creature of a mystical nature lived on the moon. When life appeared on Earth and developed, it managed to move to Earth. Here she lived well and ate any creatures, and grew to enormous sizes. The creature is afraid of the sun and is surrounded by darkness, but none of the inhabitants of the Earth was capable of becoming its enemy. People appeared, and the Druids found a way to partially pacify this creature and drove it into a cave. It is impossible to kill her, but you can limit her power. It was only necessary to observe certain rituals and put up with some sacrifices. The Roman warriors who conquered Britain decided that all the oddities surrounding Moonval were the fault of the Druids, and dealt with the Druids. As a result, this creature was partially freed. The only thing that held it back was that local residents conservatively preserved Druidical traditions and performed rituals that had been established for a long time. In our time, a Christian priest declared war on Druidic traditions. He brought Christianity to Moonval and is spreading it here. (This is very well shown by the author in terms of psychology - how a growing sect suppresses those who refuse to join it.) This plays into the hands of the creature, the priest becomes its ally. The stronger the religious hysteria becomes, the more powerful the creature gains. Moonvel becomes surrounded by thick fog. It’s always twilight here now, and it’s getting darker over time. People outside forget about his existence. The people inside need to find a way to deal with the Christian sect and the creature on their own.