The five funniest loonies of the Netherlands are back in a pleasantly disturbed family movie. Bep Brul, the Major, Fats, Mrs. De Haas and Dr. Doolittle are no longer living at Zonnedael. The mental institution was closed down, to the deep sorrow of nurse Ten Hoeven who misses her beloved patients so dearly that she has lost her purpose in life. When the nurse is suddenly kidnapped and the lunatics hear about it, they embark on a risky and reckless search. It turns out that an incredible story underlies the kidnapping mystery.