Misi Mókus was born in the spacious, comfortable den of a huge tree in the forest with his four little brothers and sisters. He was the liveliest and the biggest of the four. He could be distinguished from his siblings not only by his features, but also by a peculiar characteristic: his tail was black. Although there are species of squirrel that have black fur, Misi's family belonged to the red squirrel family. Father Squirrel was angry enough to say - Red squirrels have red tails. If it's black, it's caused by some bad spell.The parents asked Uncle Squirrel Squirrel for advice on what to do about Misi's boys' black tails. The wise old Squirrel Squirrel predicted good luck for his boys.

Most of her colleagues take Mária, the new teacher to be a communist party-worker, only Irma and the drawing teacher Zoli treat her kindly. Mária starts working with great enthusiasm, and her class learns to love her in a short time.

This entertaining film highlights the importance of integrity, justice, and appreciation for the environment. The compassionate and wise Captain is the hero, who is trying to stop long-time troublemaker and master of disguise Zero the Cat as he plans his biggest coup ever. Helping the Captain along the way are the bright Constable Eleméri Ede and seasoned secret agent Góliát. The resourceful Gólíat succeeds in locating Zero's hiding place, where he overhears part of Zero's newest plan. Although unable to get all the details, Gólíat reports to the station and it becomes clear that stopping Zero will be quite a challenge.