Our train departs from platform 10 at London's famous King's Cross station. Recently re-modelled, the station is now signalled from York, two hundred miles to the north. Before departure we take a look inside the ROC (Rail Operating Centre) to follow our train from the signaller's viewpoint. Our 8 car EMU takes the down fast line of the East Coast Main Line running at 100 mph. After racing through the suburbs of North London, we encounter the notorious two-track bottleneck of the Welwyn viaduct. At Hitchin, we diverge over a specially-built single track flyover onto the Cambridge line. Having run non-stop from King's Cross to the University City, we then call at Cambridge North, Warerbeach, Ely, Littleport, Downham Market and Watlington. The scenic Fen line, consists of both double and single track sections, terminating in the ancient port and market town of King's Lynn.