Authors note: please try to keep slow transformations over time and also the transformations should always end when the transformee becomes full anthro
Regardless of the setting--be it Central Park in New York City, the Sierra Nevada Mountains, the Great Smoky Mountains, or a European forest--the protagonists of the story find a cabin. Seeking shelter from the elements, they soon discover that no matter which way they walk, they always find themselves back at the cabin. As a result, they are cursed to slowly transform into anthro hermaphroditic versions of the animal they initially name when they approach the cabin (which can be any mammal, though you can get creative). With each arousal or pleasure, they experience a body part changing, which becomes permanent when they reach orgasm. It doesn't matter how the pleasure is induced--masturbation, sex, or rape--but if they resist climax, the transformation will reverse, though they will have a preview of the next change coming. The first change is always the tail, with ears, noses, and sexual organs coming soon afterwards. As the transformation progresses, limbs, heads, and various parts of the torso, both internal and external, will change.
The cabin is always equipped with electricity, stocked with food and supplies including some clothing, and it repairs itself from any damage. It will also modify itself and the surrounding area to accommodate certain conditions, tempt its victims, or trap them in a location. For example, if they arrive with a pack donkey or on horseback, a small pen will appear nearby; if they have a dog, a doghouse is constructed; and if they are on all fours, they may find themselves trapped in a coral with a ‘friend’, or discover a pond for fishing or idle hands. Former victims may also be drawn to these sites, further complicating the situation.
The victims must learn to cope with their alterations and find ways to make the most of their new forms, while avoiding sexual encounters at all costs. As they become more animal-like, they take on their eating habits, though they are still in control of themselves until near the end, when the animal mind takes over. If the victim is called by their human name, they may briefly regain control of themselves. When they become full animals, they will leave the cabin and wander the surrounding woods, preying upon new victims if they are found.
No one knows how to break the curse or if there is a way out. But the victims will survive and go on living, even if it means embracing the wild side of life.