Young Koko has just moved with his parents from his idyllic countryside home to a big city. There, with the help of his new friends and a neighbour he investigates the mysterious case of a dead old man who used to live in the flat he has just moved into. Koko and the Ghosts is a family film based on a popular Croatian series of young-adult novels written by Ivan Kušan.

Witty and resourceful fourteen-year-old Koko solves yet another mystery - aided by his friends. One of them, Tomo, has recently moved to the city and longs for adventure. The boys notice that their new classmate acts curiously. Step by step, joined by their classmate Marijana, they unveil the boy's dark secret.

It seems that football is still the most important thing in Koko's life and the upcoming encounter between the infamous “Pirates” and Koko's team “Green Hill” the central event of the season. Zlatko is still spending every second reading books and scolding Koko for being immature. To prove him wrong, Koko tells him that he is unhappily in love with Ana, a mysterious girl as magical as the heroines from Zlatko’s novels. Koko’s mischievous sister Marica, secretive friend Ema and insolent Melita have their own band – Koko’s team will go to a concert, as will the girls go to their football games. We will find out whether the boys are really that interested in music and the girls in football in Love or Death - the new film from the Koko serial.

Koko and his friends are spending summer vacation on the shores of a lake near the idyllic Green Hill, hanging out and playing. The magical countryside is disturbed by unusual events which alarm the children as well as the locals: under cover of night, burglars break into one house after another. When the police turns a blind eye to denunciations by adults, the children decide to take matters into their own hands and unmask the burglars.