Pod-Caverns of the Sinister Shroom OSRIC Expeditious Retreat Press 2007
Strange doings are underfoot in the wild hills bordering the realm of decent and civilized folks! Villagers and cattle have gone missing; woodcutters have disappeared; misshapen beings have been seen shuffling through the forests.
Some brave villagers have tracked a group of stolen oxen as far as the rocky banks of a small river in the hills. The trail disappeared down into a fissure in the limestone rock, where a fast-running stream plunges down to the dark caverns below.