A CRPG set in the Dungeons & Dragons setting of Planescape in which The Nameless One, an immortal amnesiac, sets off on a quest across the infinite Planes and gathers a party of conflicted companions to find out who he is and reclaim his mortality. Throughout it, he faces the consequences of the horrors he committed in his past lives and tries to find the root of all the torment plaguing his companions and the Planes.

The game's story begins when The Nameless One wakes up in a mortuary. He is immediately approached by a floating skull, Morte, who offers advice on how to escape. Morte also reads the tattoos written on The Nameless One's back, which were inked there as reminders to himself, that contain instructions to find a man named Pharod. After a conversation with the ghost of his former lover, Deionarra, and passing by various undead, The Nameless One leaves the mortuary to explore the slums of Sigil.