After a high-stakes, nighttime chase, a flying saucer is shot down, landing intact in a freshwater lake at the East Yorkshire seaside resort of Hornsea. The authorities, under the guise of discovering a small-yield atomic bomb, evacuate the entire town. John Phillips returns home to Hornsea, ignoring all warnings. As he explores the eerily silent town, now plunged into pitch darkness, his curiosity leads him to the freshwater lake. From his hiding spot, John watches as authorities haul not an atomic bomb, but a UFO out of the water. Suddenly, a bright light transfers the alien pilot's consciousness into John's mind. The boy agrees to help the alien return to its saucer. Despite being pursued by an army of security forces equipped with state-of-the-art technology, John manages to get the alien back to its ship. However, fate has other plans. What follows is an extraordinary adventure with life-or-death consequences for John.