Dead Gods (1997)

Dead Gods is a 176-page adventure book featuring two scenarios that can be played separately or linked together. In the first, the heroes are drawn into an epic quest to uncover the secrets behind the return of an infamous AD&D villain long though dead. In the second, the city of Sigil threatens to explode in a faction war for control of an old church and a mysterious force lurking within it. Dead Gods also features a MONSTROUS COMPENDIUM entry for a brand-new fiend, full-color illustrations to bring scenes alive for players, and a poster sheet of maps for the Dungeon Master.

Dead Gods builds on story elements first explored in the PLANESCAPE adventure anthology The Great Modron March, though that product is not required to use this one.

From the back of the book:

"For 4 to 6 Characters of 6th to 9th levels

Think killing a god's is tough, Berk? Try Bringing one back.
Silently, ponderously, they float through the Astral Plane, mammoth isles of rock adrift in an endless sea of silver. Once they were gods. Now they're little more than debris, petrified husks of fading belief and forgotten prayer. Yet for many, their memories linger, their dreams live on - and for some, those dreams are terrifying nightmares of vengeance, and conquest, and death.

Dead Gods, is a 176-page adventure book featuring two scenarios that can be played separately or linked together. In the first, the heroes are drawn into an epic quest to uncover the secrets behind the return of an infamous AD&D villain thought long dead. In the second, the city of Sigil threatens to explode in a faction war for control of an old church and a mysterious force lurking within it. Dead Gods also features a Monstrous Compendium entry for a brand-new fiend, full-color illustrations to bring scenes alive for players, and a poster sheet full of maps for the Dungeon Master.

Dead Gods builds on story elements first explored in Planescape adventure anthology The Great Modron March, through that product is not required to use this one"