The de Havilland Comet introduced jet travel over the Mediterranean, but a series of accidents led to investigations into reasons like human error, mechanical failure and even UFOs.

During World War I, soldiers reported seeing spectral bowmen and an angel on the battlefield at Mons. Was this a product of propaganda or an actual vision witnessed in the chaos?

In Cottingley, two young cousins produced photographs of fairies that enchanted the world and even convinced the author of Sherlock Holmes, Arthur Conan Doyle, until decades later, their trick was exposed.

Britain's real-life X-Files explore four otherworldly tales where fear, folklore and secrecy collide.

Leaf through declassified CIA files and investigate satalite images of a ship-shaped formation, The Headless Woman at St James' Park and more shocking phenomena.

From vanished pilots and psychic Cold War experiments to Nazi myth hunting, these mysteries reveal power, obsession and the unknown forces behind them.