Fulfilling an order from a young aristocrat to steal a precious cup, Conan enters the castle of a famous collector of rarities and antiques. And he ends up there literally immediately after the mysterious murder of the owner of the castle himself. An impartial investigation, launched by the inquisitor, in order to find out the true murderer, turns the attention of those present to the mysterious cup that appeared in the castle the day before. Is there a killer there? And who is he?…