On her first day in the new role, Annika and the team are called in to solve the murder of a man found in the Clyde, a harpoon piercing his head. The investigation leads them to the victim's struggling boat business, where not everything is above board.

When the body of a scientist is found in Loch Katrine, Annika is reminded of Ibsen's Enemy of the People. But with so many people wanting him dead, which one did he push over the edge?