On the night of October 21, 1978, a 20-year-old pilot flying alone over the freezing Bass Strait radioed Melbourne that a brightly lit craft was orbiting him and toying with him. Air traffic control saw nothing on radar. His final words were it's not an aircraft, followed by metallic scraping sounds and silence.

This episode investigates the disappearance of Frederick Valentich, a case that straddles tragic human error and UFO legend. We weigh his final terrifying transmissions against the physics of the world he left behind, and explore how fear, inexperience, and pop culture may have collided in a fatal moment.

• Valentich's profile: only 150 flight hours, a visual-only rating, repeated exam failures, and a documented fear of alien abduction
• The contradictory cover stories for the flight and his failure to alert King Isla ...