Professor Lyons, who devoted his entire life to the study of biblical texts, was shot dead at his home. His wife, suffering from senile madness, is found hiding in a closet with a pistol in her hands. For the police, everything is obvious, especially since everyone around knew: the wife of the murdered man was terribly jealous of her husband. But is this matter so clear? After all, shortly before his death, Lyons told several experts that he had accidentally stumbled upon the Arimathean Letter in the archives, a sacred manuscript inscribed by Christ himself. It could not be found in the deceased’s house; Perhaps the relic was stolen? But this document can radically change the face of the Christian religion. Or was there some third reason for the murder? The professor's daughter Maria does not want to remain on the sidelines: she wants to solve the crime, find the missing manuscript and clear her mother's name...