Tales of the Dark Ages (1990)

From the back of the book:

This collection has a story for everyone. With helpful explanatory notes in the introduction, even roleplayers unfamiliar with the Ars Magica fantasy role-playing game will find this a valuable gaming aid. "Out of the haunted mists of the past come... Tales of the Dark Ages. A collection of adventures for the Ars Magica game, featuring:

The Ghoul of St. Lazare by John Nephew: A horribly mutilated body floats downstream to the players covenant. It is discovered that the pox killed the unfortunate girl - and afterwards someone did this to the corpse. What evil brews upstream? Diabolists, a necromancer, or worse? In the course of their investigations, the characters encounter a bizarre priest, twisted by lies and secrets of the dark past, who has lost much of his hold on reality. What evil fate awaits him and the investigating adventurers?

Copse of Skulls by Thomas M. Kane: When a novice sorcerer of the covenant, dispatched as a messenger, disappears, word returns that he unleashed a nameless horror from the wood known as the Copse of Skulls. Now the player characters are dispatched to rectify the situation, and free the sorcerer - if he yet lives. To do so they must face bandits who are not quite human, and the forest's monstrous master - to whom the ancient pagan Celts sacrificed human skulls; as well as challanges of a more subtle character.

Tongue of Vipers by Thomas M. Kane: Magi of the players' covenant are invited to the court of the Viscount Stutt von Orstadt, in the Lorraine region of France, at the behest of Lady Clair, a member of the court. When the PCs arrive, they find that their would-be hostess has been accused of attempting to poison the count! Can they find if she's really guilty - or who is responsible - while avoiding suspicion themselves, and winning access to the viscount's treasured, magical Seir Waters?

The Inheritance by James P. Buchanan: A companion of aristocratic lineage has been bequeathed a holding of land. When he and his friends journey to it, they find it holds an ancient Roman aqueduct. If they could restore this aqueduct to working condition, drought in their tenants' lands may be alleviated. But there are ancient forces which oppose such meddling...