Mathias Crane is a newly appointed British captain of a late 18th century trade vessel. He's poised to embark on a routine expedition delivering goods to foreign nations around the horn of Africa when complications arise before he's able to set sail. A mysterious and powerful man brutally slays a young woman within the bowels of Mathias' ship, the Anne-Marie. Mathias attempts to hide the evidence of the event as best he can before the crew arrives to make way the following morning.
Over the next few weeks, events have Mathias questioning whether or not the murdered woman has truly left the ship, as fatal incidents begin to befall crew members. Mathias finds himself in a race against time to unravel the mysteries surrounding the Anne-Marie and its connection to the woman murdered inside. After all, there's no point trying to command a ship if there's no one left alive to sail it.