In the spring of 1986 at the Chernobyl Nuclear Power Plant an explosion occurs. At the same time a girl called Mimi arrives in a small village in western Finland, and immediately fills 15-year-old Mariia’s life with radiating light. 20 years later Mariia returns home to take care of her sick mother, and memories start rising to the surface though she tries to fight them back. The summer Mariia and Mimi got to spend together two decades ago, was full of fierce joy of discovering what life could perhaps be. The love they had was magical and powerful but still Mariia couldn’t save neglected and abandoned Mimi from herself. After the summer Mimi dies by suicide, and years after the tragedy Mariia needs to remember the light, so that she can also accept the dark in her past. And forgive herself.