“As he chatted to his housemate in the sunshine, planes on their way to Heathrow airport made their final approach overhead. On his phone, Wil showed his housemate an app that tells users the route and model of any passing plane. He tested the app on one plane, and then held his phone up again, shielding his eyes from the sun and squinting into the sky. Then he saw something falling.” Out of thin air: the mystery of the man who fell from the sky.