Luke is on a school trip in Rome when he unwittingly becomes a suspect in an investigation to uncover a stolen painting. Luke does some investigating himself and uncovers a gang plotting to break a secret code that has obsessed treasure-hunters since the darkest days of the Second World War.

The Ocean Emerald is a floating luxury palace. A cruise ship carrying 1,000 wealthy passengers. He only boards the Emerald to return a lost passport, hoping for a finder's fee and a glimpse of the ship.As the ship sails across the stormy Baltic towards certain Hell, will Luke be able to escape and save the terrified passengers around him