After two years of work, engineer Anita and her team are about to break through a concrete wall separating her new passenger tunnels from those of Crossrail, the giant east-west rail link being built across the capital. Meanwhile, the network takes delivery of 192 multimillion-pound trains, which are put through the `rattle test' before being pressed into service, while customer service assistant Stan prepares to say goodbye to the Underground after 35 years' service. Last in the series.