Nina Borg, a Red Cross nurse, wife, and mother of two, is a compulsive do-gooder who can't say no when someone asks for help—even when she knows better. When her estranged friend Karin leaves her a key to a public locker in the Copenhagen train station, Nina gets suckered into her most dangerous project yet. Inside the locker is a suitcase, and inside the suitcase is a three-year-old boy: naked and drugged, but alive.
 
Is the boy a victim of child trafficking? Can he be turned over to authorities, or will they only return him to whoever sold him? When Karin is discovered brutally murdered, Nina realizes that her life and the boy's are in jeopardy, too. In an increasingly desperate trek across Denmark, Nina tries to figure out who the boy is, where he belongs, and who exactly is trying to hunt him down.