A Finnish music comedy set in the ealy 1960s.
Uuno Turhapuro's younger brother Peni arrives in Helsinki. Uuno helps his brother in management duties.
Uuno Turhapuro reads guide books to learn how to be an orchestra conductor and a secret agent. Meanwhile, his father in law hatches a complicated scheme to finally get rid of Uuno.
Uuno Turhapuro finds his doppelganger, Hugo, who happens to be a computer genius. Hugo helps Uuno save his father-in-law's business (and Uuno's inheritance) while Uuno helps Hugo win the heart of the love of his life.
