Oublié Cathedral is a fictional cathedral that exists in Eternal Darkness: Sanity's Requiem. Located in Amiens, France, it serves as the setting for three of the game's chapters. Despite its outward appearance as a house of god, the forces of darkness work their way inside and corrupt its purpose, turning it into a base of operations of sorts.
The first time the player visits Oublié Cathedral, the larger cathedral structure has yet to be built; rather, it is still a simple chapel. Anthony, a servant loyal to Charlemagne, is struck by a curse in a scroll meant for his liege, and runs to warn Charlemagne about the threat to his life.
As Antony approaches the church, his body warps and decays due to the curse's effects. By the time he reaches his destination, he is reduced to shambling about and unable to fight with the strength of the youthful man he once was. When Anthony finally reaches his destination, he learns, to his horror, that the conspirators had arrived first and had already killed Charlemagne. Anthony collapses, done in by his curse and despair.
Paul Luther's Chapter
Centuries later, the traveling monk Paul Luther arrives at the now complete Oublié Cathedral hoping to see a fabled artifact known as the Hand of Jude. However, within minutes of his arrival, he discovers the mutilated corpse of a murder victim and, upon summoning the guards, is detained as a suspect.
Paul manages to escape his confinement and makes his way down to the inner-workings of the cathedral, contending with horrific, ungodly abominations along the way. At one point, he finds the now zombified Anthony, carrying a sword and crying for his liege, as the forces of darkness have left him locked away to serve as an undead guardian of a special jewel. Paul fights and defeats Anthony, and then prays for the undead man's soul as he is finally allowed to die.
Paul comes to realize that the cathedral is not what it seems. There is no Hand of Jude; the story of the artifact is merely a ploy to lure holy men to the church so that they may become human sacrifices. Making his way to the cathedral's inner sanctum, he intends to put a stop to this heresy, but is shocked to discover that Pious Augustus, the leader of the forces that serve the ancient behind the conspiracy, has summoned the Black Guardian as a means to guard the artifact representing the ancient that Augustus's master is weak against.
Helpless to do anything that could stop the Black Guardian, Paul is killed by its might instantly.
Peter Jacob's Chapter
During World War I, Oublié Cathedral is converted into a field hospital. Peter Jacob, an American journalist, comes to stay at the cathedral during the height of the war, when numerous wounded are brought within its walls to ostensibly seek treatment. However, like Paul before him, Peter quickly learns of the corruption within the church; the wounded are being sacrificed to the darkness.
Peter retraces Paul's steps, and he too confronts the Black Guardian. However, unlike Paul, he also has the magical means to fight back. He kills the Black Guardian, one of the game's few true boss fights, and takes the artifact it had guarded for so long away.