Elminster in hell

the long version

Hell hath such fury. On the world of his birth he's all but a god, but when an ancient evil banishes him to the depths of the Nine Hells, he's just another lost soul. Elminster, Sage of Shadowdale, Chosen of Mystra, faces his most desperate struggle—to survive, to escape, to cling to his very sanity—and all the forces of the inferno are rallied against him. Captured by a powerful demon, the Forgotten Realms legendary wizard is imprisoned in hell and tortured for his most prized and valuable possession—his mind. To resist means certain death, but to give in means absolute madness