Treasure Most Magical

From the publisher: "Tuwunux is a renegade troll, and enemy of all civilized races. Elders spat his name and cursed his line, long before your time. But the adventurers have got him on the run, cornered in a dungeon, or do they? It turns out the troll's interests aren't strictly of this world, and the adventurers must follow him across a gulf of death to an alternate dimension, from whence a safe return is far from certain!"