The Graywall Incident is an adventure module by Tim Sech and Stephen Radney-MacFarland set in the Eberron campaign setting using the 3.5-edition Dungeons & Dragons rules and designed for the RPGA's Mark of Heroes campaign. It was released in 2006. It includes art by Jacob Burgess. It is intended for four or five 7th-level characters.
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Monster City!
Beyond Breland's western border lies a kingdom of monsters ruled by hags called Droaam. The gate to this kingdom is the savage city of Graywall.
The Graywall Incident is an adventure for the Dungeons & Dragons game. It can either be played as a stand-alone adventure, or as part of the Mark of Heroes campaign offered by the RPGA. It is designed to challenge 7th-level characters as they search to secure a magical artifact from an ogre mage.”
— Back-cover text