D&D 5E: Adventure: Fifth Edition Fantasy #31: Idylls of the Rat King

Goblin bandits are once again attacking the caravans laden with silver ore, killing innocent miners, and stealing cargo. The goblins have taken up residence in an abandoned mine northwest of Silverton. Someone must get rid of them. But this is no ordinary abandoned mine. It was deliberately barricaded generations ago when the Gannu family, founders of Silverton, discovered an unspeakable evil on its lowest levels. And these are no ordinary goblins, for the curse of the Gannu family courses through their veins...