Mystery of Soft Machine(ソフト・マシーンの謎Sofuto Mashīn no Nazo) is the fifth story arc in Vento Aureo. It narrates the ambush of Bucciarati's Gang by an unknown Stand as they head to Capri to retrieve the late Polpo's treasure and the investigations of Bruno Bucciarati and Leone Abbacchio with the aid of Abbacchio's Moody Blues.