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...