Johan Falk (Jakob Eklund) and the rest of the cops at GSI have been instructed to get to the bottom of a prostitution ring consisting mostly of women from eastern Europe. Johan recruits Hanna (Anna Antonowicz) a young woman from Poland who tends bar on a German cruise ship, and a friend of one of the prostitutes who recently turned up dead. At first reluctant, Hanna is soon deep undercover and perhaps a little too eager to help, but with her assistance Johan and his team are soon on the right track and find themselves wrestling with bigger ethical dilemmas than ever before.