Rosa Maria is a young history professor traveling with her daughter, Maria Joana, on a cruise through the Mediterranean to Bombay where they will meet her husband. This cruise is taking them to places never visited before--Ceuta, Marseille, Pompei, Athens, Egypt, Istanbul--and the trip becomes a journey through history. She meets well-known figures of different nationalities: a French businesswoman, an Italian former model, and a Greek teacher and actress; and the captain, an American of Polish origin. But when a strange threat disturbs the cruise and menaces the ship, together they are all forced to deal as passengers in the same boat.