Curse of the Obsidian Knight

From the description: Deep within the 4th Hell in the shadow of towering creatures lumbering about with impossibly long limbs, some of them miles long, sits a Keep made of rough-hewn Obsidian. Accessible only with the singular matching key, this fortress of fear is home to a most conniving and wicked knight, a singular force of twisted plotting and evil. What treasure awaits? What will you do for adventure and glory? Curse of the Obsidian Knight is a small, OSR-style adventure. The stats are for Basic Fantasy Roleplaying Game, but should be easily adaptable to just about any RPG of your choice.