Eternal Darkness: Sanity's Requiem is a horror action-adventure video game developed by Silicon Knights and published by Nintendo for the GameCube. The game was originally planned for the Nintendo 64. The game's setting is centered on a mansion in Rhode Island—the home of protagonist Alexandra Roivas' grandfather—and a book that Alexandra finds there. It utilizes a third-person view in which the player must navigate a number of locations as twelve characters spanning different time periods, as well as "sanity effects" to enhance the gameplay.