La Regina del Mare Adriatico Arc or The Queen of the Adriatic Sea Arc is a story arc in Toaru Majutsu no Index. The arc is concerned with Kamijou Touma mysteriously winning a trip to Northern Italy despite his misfortune. Here, he is suddenly caught in another conspiracy by the Roman Catholic Church, this time regarding the mobilization of an ancient weapon against Venice – The Queen of the Adriatic Sea. This arc would mark the Roman Catholic Church's final time as the antagonists before the intervention of God's Right Seat.