Leon, a member of a space research center, notices that the central camera is malfunctioning. He sets out to find out what the problem might be. Soon he meets a woman named Kata, who explains that an alien named Killer is responsible for it, who is seeking to destroy the world.

The documentary shows how the Hungarian sci-fi film Gyilkoló (The Killer) was made.

After a chance meeting, Zsolt and Ildikó delve into the mystery of the enigmatic Horsehead, uncovering eerie clues to unveil the figure's true identity and motives.