The series "Springfloden" is a Swedish-German detective thriller about a talented student at the police academy. Olivia Rönning must present her graduation project in her field of study - investigating a particular murder. She chooses an unsolved case from 1987 as her basis. Back then, on the island of Nordkoster, three unknown individuals buried a pregnant woman in the sand, who drowned during high tide. The only witness to the murder was a nine-year-old boy, so Inspector Tom Stilton couldn't prove anything.