Season 4 - Episode Guide

Cheltenham races sees thousands of extra passengers arrive - many of whom fancy an early morning tipple - while chaos ensues when a passenger chases a fraudster round the station, accusing him of selling her out-of-date football tickets. In Swindon, the control room staff hear that heavy rainfall might cause flooding and block the mainline to Cornwall - leaving them facing a big decision.

The summer heat has caused a points failure at Didcot, leaving the Paddington team anxious that the problem gets resolved in time for rush hour. British Transport Police are not impressed when a young man jumps onto the tracks to retrieve a sleeping bag seconds before a 400 ton train rolls by, while in Teignmouth, the line has to be closed when an unexploded Second World War bomb is discovered just over 200m from the station.

Autumn gets off to a wet start when the roof of Paddington begins to leak during torrential rainfall, and with gales of up to 90mph, Network Rail staff brace themselves as a storm closes in on the UK. A flyaway plastic bag causes a loss of power, trapping three trains and disrupting Paddington's peak service. Mobile operations manager Jane is called out when a van hits a low-level bridge, while British Transport Police in Bristol Temple Meads get more than they bargained for when they search a teenager suspected of using drugs on board a train.

The station shuts for four days over the Christmas holidays, though staff are still needed on site as they face the disruption of track and engineering works. Up the line at Oxford, workers are laying a whole new track system. Luckily, they have the Kirow Crane to help them - a multi-million-pound lifting machine that can lay over 100 tonnes of track at a time. At Swindon, specialists work to install 30 new booms to support the overhead lines for a new generation of electric trains. Weighing up to 15 tonnes, they need to be carefully lifted into place. However, bad weather threatens progress.