To celebrate its 50th anniversary, the railway has hired headlining steam engine Royal Scot, but she has a problem with her boiler, carriages that haven't been serviced in five years, and no-one even knows if she will fit the line.

The marketing manager targets teachers in hope they'll return with students, Chris reveals how some bridges are in desperate need of repair; Piglet has a race against time to fix an engine which is hoped be on display for the Tour de Yorkshire.

The busy summer season is looming and the steam engines are old, so there's always something to fix. The only chance of getting through the summer is if they complete the overhaul of Repton, a 1934 Schools class engine.

A summer heatwave brings record numbers to the railway, but also risks fires in the dry national parks through which the line runs, putting the very existence of the railway in danger.

Head boilersmith Mark and his fiancé Emma choose their beloved B1 steam train to lead their wedding, but not everything goes to plan.

For the annual Gala Festival, the NYMR plan to swap their precious Q6 engine with another from the Severn Valley, but there is a crack in the engine box and no one to fix it on short notice.