In the early '60s, 3 Danish classmates join a "den"/tree house. Steen likes his pet fish Zappa because it eats the weaker fish. Bjørn attracts girls and Mulle is a talkative, strong boy. Steen gets them into burglary and later escalates.
Denmark, 1963: Teenagers Bjørn and Erik are into girls and being in a band helps Bjørn meet Anna. Erik likes Kirsten but she likes Bjørn. Having a mentally ill mom at home also ruins Erik's chances. Anna's pregnancy changes everything.
