This is one of the Reverend Awdry's final books, and the last one to focus on the mainline characters. It was published in 1968, which was siginificant as it was the final year of steam on British Railways. The is constantly referred to throughout this book, with the threat of dieselisation, the fate of steam on the British mainland, and the daring escape of one engine from scrap. However, the book proves Sodor to be a safe haven from the threats of the mainland, with the reassurance that steam will continue there. Flying Scotsman pays a visit, and, at a time when branch lines were closing down, here, one re-opens, with a new tank engine, Oliver, who has escaped the scrapyard, called in to help run it. It is often said that this is one of the darkest books in the series, and with the constant theme of scrapping, perhaps it is, but it also manages to provide the usual humour and banter, and in all, has to be one of the most memorable books in the series.