On Australia Day in 1966, the three young Beaumont siblings took a five-minute bus ride to Glenelg Beach in South Australia and never returned home. Numerous credible witnesses reported seeing the children playing comfortably throughout the day with a tall, blond man. The strangeness of the situation was compounded when the eldest child, Jane, was seen buying snacks with a one-pound note, a denomination of currency her parents had not given them. In the mid-afternoon, a trusted local postman saw the three siblings walking alone and seemingly happy away from the beach, after which the trail went completely cold. A massive police investigation turned up no definitive trace of the children, leaving their ultimate fate one of Australia's biggest mysteries.