From publisher blurb:
Flik Silverpen's Guide to the Fiery Caldera is a dungeon crawl through a dynamically changing system of treacherous lava tubes. It works great as a one-shot, or the perfect continuation of the Dragon Town campaign setting, specifically after the events of the Red Growth (FSG 06) adventure.
The Ancient One, a collossal magma tortoise lives deep underground in a lake of lava. She has a quest for the adventurers, explore the lava tubes surrounding her lake and find out why the Ember Trolls are acting so strange. But be careful, there are many dangerous creatures about and the lava is VERY hot.
This adventure is filled with whimsical illustrations, a changing map, unexpected random encounters, lots of fun magic items, and some seriously weird NPCs. Combat encounters include references to comparable 5E monster stats, otherwise, the zine has everything a DM needs to run this crazy dangerous one-shot!