The Northern Lights was first broadcast on BBC One in 1969 and followed the Pole Star, a Northern Lighthouse Board relief vessel and her crew as she serviced some of Scotland's most remote and inaccessible lighthouses. Although the Northern Lighthouse Board had begun the process of automation by then, several manned lighthouses remained and the crew of the Pole Star had the crucial role of taking relief crews and supplies to these lighthouses. In this programme, the Pole Star visits the Sule Skerry and North Ronaldsay Lighthouses in Orkney as well as the mysterious Flannan Isles Lighthouse where three lighthouse keepers disappeared in mysterious circumstances in 1900.