Conclusion of Mordant Ruins
The party has uncovered the gruesome secrets regarding the deaths of regional patrols and caravans. Many were devoured by Melchior Vossen's black dragon, trapped in a cavern, guarding the castle library's secrets for centuries, feeding off of carrion and any passerby who sought refuge in the caverns. Denizens of the castle were also to blame, with blood hawks poisoning victims who journeyed near the castle, only to succumb some time later to the ill effects of their diseased bites. Other patrols were eaten by trolls or dopplegangers or became the unwilling servants of a yellow musk creeper, turning them into mindless guardians. The book found in the nearby tomb was discovered to be a manual of alchemy and helped the adventurers to create black powder with which they used to free the dragon. The dragon, against its usual nature, left with a thankful departure leaving behind a horde of arms, armor, and treasure. They then descended into the library, no longer blocked by the black