Simon (Bill Skarsgård) is a boy with Asperger's syndrome. He is a physics genius, but he cannot stand physical contact with people. He has severe obsessive-compulsive disorder and everything must be carried out according to plan. When he is unhappy, he will treat the tin barrel as a space capsule and hide in it and refuse to come out. Simon's guardian is his brother Sam (Martin Wallström), and only Sam can understand him since he was a child. Sam's girlfriend broke up angrily because she couldn't stand living with the brothers. Seeing his brother immersed in depression and sadness, Simon, who has been taken care of, decided to take care of his brother once: he would use scientific methods to help Sam find a new girlfriend...