Mind you: this is a second-hand product! It is in excellent condition though.

The Eternal Boundary is a Planescape® AD&D 2nd-edition adventure module. It is the first adventure for the Planescape setting, and focuses on a few key areas of Sigil. The player characters are hired to locate a madman who holds the key to a portal, and explore the slums of the Hive, meet the Bleak Cabal at the Gatehouse, and parley with undead in the vaults of the Mortuary.

A planescape adventure that starts in Sigil. Inside this crossroads to the planes, a sinister plot unfolds, leading the heroes into the most dangerous and desperate part of town - the ramshackle slum known as the Hive in search of a madman names Eliath, who has information the PCs' employers want.