The main characters have received an invitation to a shipboard party from Prince Rosso of Ancyra, the country of pirates. When I heard that it was a party, I thought it was a luxury cruise ship, but the ship I saw in the port town was in tatters. They board the ship with the escort of Prince Douglas, who they met by chance, but Prince Rosso has no recollection of sending out an invitation and is mistaken for an intruder. Who sent the invitation? The main characters participate in the party even though they are suspicious.