Olive is an introverted boarding school student with a very intense inner life. She has created an imaginary world she visits whenever she wants to, a world turned upside down by the arrival of Lenny, a sick and injured astronaut. She realizes that Lenny actually exists and that the capsule that brought him back from a space mission crashed somewhere on Earth – where exactly, nobody knows. With the help of her extroverted roommate, Charlie, Olive journeys deep into Siberia to save the life of this complete stranger. This is the long-awaited fourth and final installment of an unforgettable coming-of-age adventure.