From the Introduction:
Tyr is a city-state in chaos, and paradigms across Athas are snapping. Kalak, one of the nearly omnipotent sorcerer-kings, is dead. A band of rebels, now known as the Deposers of Kalak, laid low the centuries-old tyrant. In the wake of the great arcanists’ downfall, the city’s oppressive order has crumbled. Factions
struggle for power, snatching at scraps of influence and wealth as templars, Kalak’s agents, struggle to reassert civic authority.
Revision by Baz Stevens from an original adventure by Chris Tulach. Original version to be found at the Wizards of the Coast website.