Rebecca is kidnapped by the MI6, and Robson calls for Lupin's help. Lupin finds out that the MI6 is looking for the researches of Rebecca's lost love, Kou, a young japanese scientist who died some time ago. Since the MI6's italian headquarter (located in the basement of the ancient Teatro di Marcello in Rome) is impregnable, Lupin manages to trick Nyx in order to make him escort Rebecca outside the building, but when Robson, to protect her mistress, threatens to hurt Nyx's family, the agent goes berserk, attacking his own companions when they try to stop him; then, despite being branded by the MI6 as a traitor, he starts searching for Lupin in order to exact his revenge.