2028, somewhere in northern France. Lázaro and Tristán (19), twin brothers and best friends, are training together for the Astronaut Academy entrance tests. One day, Tristán is contaminated with some mysterious residue which makes him monstrous physically, weakened mentally and fluorescent at night. This disaster forces Lázaro to let go of how he remembers his brother and learn to love him as he is now, in a world where there is no room for monsters.