In 2009, James May went on a quest to show what was possible to achieve with old-fashioned toys by using them on a scale never seen before. Five toys were successful, but one failed - model trains. James and his team revisit the doomed challenge and make another attempt at building the longest ever model railway track - nearly ten miles long.
Linking two Devon towns, Barnstaple and Bideford, the last attempt saw no trains reach their destination and James's cherished childhood toy, the Flying Scotsman, fail to even make it out of the carpark. This time the feat is bigger than ever before, as James challenges the two German proprietors of the world's largest toy railway museum to a race along the track.
The locals of both towns are galvanised once again and James's old friend and railway enthusiast Oz Clarke turns up to lend a hand. Will the people of Devon ensure that for the first time in a generation, a train - however small - makes the journey between the two towns?