Pertsa and Kilu's imaginative plans become all too real when they find themselves on the trail of a bank robber and a missing yacht.

Pertsa and Kilu are two neighbour boys with different backgrounds. They live adventurous life of a young imaginary mind in small harbour town. Accidentally they get involved in a bank robbery. Through their own investigation of the case, imagination and real danger gets mixed and leads to great adventure where friendship and courage is on stake.—themoviedb

Handy, creative schoolboy Pertsa and his younger buddy Kilu have lively imaginations. They are however right when they link the sinking of a yacht hey witnessed just offshore their small harbor home town and the robbery of the only bank, which the only police detective can't properly investigate. They also need money for their summer holiday plans, so go for the hefty reward attempting to salvage the loot from the wreck. Thereto they attempt building a raft, aircraft and submarine. Pertsa even perseveres after their parents ban such projects and separate the mates. The fiends also cause and meet problems.—KGF Vissers