The Pit

From the introduction: Long ago, the land was infested with goliath-sized worms. Stretching across miles of mud flats in the kingdom of Sujikistan are enormous worm tunnels. Rumor has it that the goblin king has taken up residence in one of these, mining the ground for all it’s worth. It is also said that a dark wizard of unimaginable power dwells here. Recently villagers from a nearby town have been disappearing, supposedly kidnapped by the wizard.