Detectives set connection of a few crimes with the ancient finger-ring stolen from the Hermitage and disappearing in the criminal world. The known historical figures possessed them, including famous magician Калиостро. Mystic capabilities add a finger-ring, his properties are studied by scientists, he appears in the field of interests of gangsters, militiamen, underground smart dealers. Thus constantly a question gets up about the cost of treachery, possibility to justify him, and about the concept of treachery. Is ambiguous interpretation how really here possible? And does time to soften the estimations of one of the most ancient biblical sins can?