Marc de Segur, heading to the estate of the Count de Fontaine, was looking forward to a quiet rest in the company of his old friend. He did not even suspect that he would soon be in the castle, which is going to storm a small army. However, barely averting this threat, Mark falls into the whirlpool of events associated with a strange relic in which, according to legend, the key to the treasure of Diana del Reo, Countess de Pontier is hidden. No one knows what kind of treasure it is, but too many people want to get hold of it, and the events surrounding it are becoming increasingly sinister. And Mark will risk his life to investigate a mysterious murder, escape from a demonic beast and find out who is behind a series of magical attacks, the victims of which were not only himself and his friend Fontaine, but also other people. Will he be able to cope with a mysterious and cruel killer and finally reveal the secret of the treasure of Diana del Reo? In this difficult case, he again comes to the aid of the nine-tailed fox Lee Jin Ho .