Emma Bergkvist lives with her sister Josefin, mother Carola, father Pierre, and nanny Åsa in a house outside Stockholm. Her father is a researcher at Swedish Energy Testing and has found a solution to the world's energy problems. He has succeeded in extracting energy from pure water. It is nighttime, and an intruder has broken into the house. The flashlight shines on the sleeping children. Emma wakes up and calls for her mother, who comes and tries to comfort her from her nightmares. Emma insists that they are not nightmares, but that there are thieves in the house.