Elminster in Hell is a 2001 fantasy novel by Ed Greenwood, part of the Elminster series set in the Forgotten Realms universe. The story follows the legendary wizard Elminster after he is imprisoned in the Nine Hells by a powerful demon who tortures him for his mind. The novel is structured as an epistolary novel, using memories to tell the story, and explores Elminster's struggle to survive and maintain his sanity against the forces of hell. 
Plot and structure
The premise: Elminster is captured and banished to the Nine Hells, where a demon tortures him for his mind. 
The conflict: Elminster faces a choice between death or madness, as the demon tries to break him. 
The structure: The novel is told through a series of memories, interspersed with mental dialogues between Elminster and the demon, Nergal. 
The themes: The story is an epic quest that also delves into the profound struggle of one man's memories and his fight for survival.