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.

"Hladnokrvno" is a story about three friends in post-apocalyptic world. They must survive in this cold world as they confront with some unexpected enemies.

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.