From the back of the adventure:
An End to Tyranny?The High Lord is dreaming again. In his new dreams he sees a bold plan to end the tyranny of the Llorkh Zhentarim. He's counting on you to take the first steps in making his dream a reality.
Tyranny is an adventure for the Dungeons & Dragons (3.5 Edition) game. It can either be played as a stand-alone adventure, or as part of the LGR - Legacy of the Green Regent™ campaign offered by the RPGA. Designed to challenge 6th-level D&D heroes, it sends the PCs on a search for an artifact beyond the Heart of Bane itself.
To use this adventure, a Dungeon Master also needs the Player's Handbook (D&D 3.5e), the Dungeon Master's Guide (D&D 3.5e) and the Monster Manual (D&D 3.5e). This adventure is set in the Forgotten Realms game world, and it may also be useful, but not necessary, to also have a copy of the Forgotten Realms Campaign Setting.