On the morning of January 30, 1889, the Archduke Rodolphe de Habsbourg and his mistress Marie Vetsera were found dead. The remains of Rodolphe are discreetly repatriated to Hofburg, while that of Mary is hastily thrown into the depths of a tomb.
An all-expenses-paid international search for a rare copy of the book 'The Nine Gates of the Kingdom of Shadows' brings an unscrupulous book dealer deep into a world of murder, double-dealing and satanic worship.