Things kick off with a day of severe disruption on the railways as a train loses power on the East Coast Main Line, blocking services in and out of King's Cross and a domino effect causing problems all along the Line.
A specialist fire brigade response team are called after a woman falls between the platform a moving train and becomes trapped on the tracks. Staff are tested when a Tube strike hits London.
P.C. Aidy Young patrols the station keeping order, Michael from Network Rail responds to reports of a suspicious bag. An aerial survey specialist uses thermal-imaging to inspect hundreds of miles of track by helicopter.
Christmas Eve marks the start of an ambitious programme of engineering works as Network Rail staff embark upon 200 maintenance jobs around the country. Cameras follow teams in Newcastle and Leeds.