Friendship, courage and ingenuity are put to the test once again as Pertsa, Kilu and Pirkko embark on an epic adventure to solve the mystery of an old map. Twin girls Vappu and Kerttu also join the flight, and the suspense is increased when the cunning criminal Annabella Pehko jumps on board as a stowaway.

Everything is on track in the life of the beloved but eccentric surgeon Petteri Holopainen but when a patient close to him is rushed to the hospital, nothing can go back to the way it was. Holopainen loses everything he holds dear. When a familiar person from the past enters his life, Holopainen must decide what still matters.

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.