Secrets of the Railways - Season 1 Episode 2 -

The Harz Mountain Railway in Germany - Europe's longest rail network - which still uses steam locomotives and has a hidden past. This historic railway is the stuff fairy tales are made of, complete with a vintage steam train making its way through picturesque German villages, and ancient forests of the Harz mountains. But its past is scarred with haunting secrets. It holds tales of witches, human suffering, and a top-secret Nazi weapons programme.