There are reports of a monster that lurks in the tops of trees and drops down on unsuspecting people. It causes them no damage but it frightens them with a hide-like face with big dead eyes, drooling and barking like a dog while unsuccessfully attempting to have intercourse. The PCs investigate and find that it is the local village moron that is doing the spelunking in the woods. How can they explain this otherwise pleasant and merry man that it is wrong to put on a mask, drop down from trees and attempt intercourse with relatives and neighbours.
The babies of a small village has been disappearing lately, rumour has it that a demon living in the forest has taken them. The monster has the appearance of a shriveled old woman. A hag, disheveled, with maniacal appearance, wild-looking hair, and an oversized gaping mouth. Long pendelous breasts. The villagers say she eats the newborns and has sharp claws that are created for mangling. No one dears to challenge her, enter the PCs.
The road has never been more than an overgrown mud track, little travelled and little cared for, petered out to nothing more than a flattened earthen line, barely distinguishable from the rest of the landscape. The soil is dark and fecund and dark oaks stand like sentinels at the forest edge, their branches high and leafy. From them hang grizzly human bones, skulls and shiny precious stones. Who put these strange totems there? Are they warnings? Do the PCs dare to take the stones?
The PCs see a large oak tree, a curious species of yellow and black butterflies swarm around it. Upon further inspection they find that the tree is hollow and that there is an underground cave in it from which the butterflies appear. Will they inspect this strange cave?
Some parallel worlds have different time-flows, like the fabled dwelling-places of the elves: those who visit them under the hill for a night return to find that years have passed in this world. Perhaps it is the gate leading between the worlds which causes the alteration. If a gate were 'misaligned', the shift from '| |' to '| \' or '| /' as it were would lead to that difference, much as a light-beam split and bent by a prism ends up taking a longer path. There might even be a mathematical function linking degree of misalignment to alteration of time-rate.