*The Eternal Light of Day* tells the story of Luce (Anna Mangiocavallo), an 8-year-old girl who is as curious as any child her age. Ever since she was born, she has suffered from SCID, an extremely rare immune deficiency disorder. Even a simple cold could kill her. For this very reason, the little girl is forced to live inside a sterile glass chamber. Taking care of her is her father, Renato (Claudio Amendola), a loving father willing to do anything to see his daughter grow up. It’s a story like many others, except that this one begins where the others end: with the end of the world we all know. When Luce was just a newborn, a mysterious event decimated the world’s population, and now she finds herself among the few survivors. The two lead a humble existence on canned food and the occasional eel caught in the pond near their home—an old farmhouse tucked away in the Agro Pontino. She has never known the outside world, and because of that mysterious apocalypse, she never will. Everything she knows about the world comes solely from the stories told by her father, who lives alone and is haunted by the ghost of his ex-wife Helena (Dagmara Brodziak) … Then, one day, a mysterious note appears on their door: “It ends here; you are no longer safe” …