Uncle Georg takes Bertram and Winni to the Glyptoteket, where their father has become a custodian. Bertram has taken his latest painting 'Bertram and the Five Lions' with him, but during a theft his picture is exchanged for an expensive painting, and Winni is taken hostage. The villains put the family together in Tivoli - but unfortunately for them, Bertram is here at home.—Nordiskfilm