Engineers battle the elements after extensive flooding, while station staff try to deal with stranded passengers demanding answers. Graffiti artist Banksy leaves a Christmas gift.
London Euston is evacuated during the Friday rush hour - leaving passengers stranded. Driver Andy reveals how close he came to disaster. Dispatcher David imparts his wisdom to a new recruit.
The rail mobile detection team make a remarkable discovery. A high-tech home has been erected illegally under an arch complete with electricity, running water and TV. Who has been living here ?