Story
The story follows two men, Hiraga Josef Kou and Roberto Nicholas, who work for the mysterious organization The Seat of the Saints, an element of the Vatican dedicated to investigating alleged miracles; during their work, they usually find themselves involved in mysterious murder cases, which they often end up investigating.

Eventually they cross paths with Galdoune, an ancient organization that secretly aims to control the Vatican and since the Middle Ages is involved in obscure alchemic and scientific experiments in search of a way to reach immortality.