On the way to a romantic weekend, writer Erica and her cop husband stop in Kungshamn to investigate the possible murder of two French scuba divers, declared an accident by the coastguard. It may be related to an 1820 shipwreck.

The young coast guard and diver Jessica finds two dead scuba divers after a storm. She disagrees with her superiors that it was an accident and seeks the help of her childhood friend Patrik. Patrik and Erica, who are on their way to a romantic holiday, make a detour to the beautiful village of Kungshamn. They soon become involved in the case. Erica hides her real identity as the policemans wife and is invited to join the museum association. Already during the first meeting she attends the associations chairman is found murdered... The three deaths are now officially opened for investigation, and the common denominator between the victims seems to have been an interest in the wreckage of a 1820s ship. Did somebody finally find it? And what cargo did it carry? What caused the ship to sink?—Tre Vänner