人間の住む「物質界アッシャー」と悪魔が住む「虚無界ゲヘナ」。本来は干渉することすらない二つの次元だが、悪魔はあらゆる物質に憑依し、物質界に干渉していた。しかし人間の中には、そんな悪魔を祓う『祓魔師』が存在した―。

Much more than just the world's largest Cross: the Valley of the Fallen [Valle de los Caídos] is history carved in stone. It's the Basilica, the abbey, the College-Choir School, the guesthouse. Besides being a place of worship, since 1958 it has been home to about twenty Benedictine monks. Some of the first ones still live there. It also housed, until 1982, the Centro de Estudios Sociales [Center for Social Studies]. All of this is now under threat.

This documentary aims to shed light on the history and significance of the Valley of the Fallen, explaining when, how, and why it was built, while debunking the main myths surrounding it.