This is book 3 in the series. Peter and his Grandpa have built a miniature steam railway across their farm, linking their houses. It is a scenic journey, crossing fields, woodland and running beside a river. In this third book they extend the line to Yockletts Village. They tell Grandma the extension is for her to go shopping, but they have a secret plan to run trains at high speed. Along the way the two heroes discover a long forgotten traction engine which they put back to work and Grandma has a hair-raising escape. To celebrate the opening of the new line, The Great Train Race is organised with lots of visiting locomotives. Who will win? As in the previous books, the technical information and diagrams are at the end of relevant chapters, explaining how railways and engines work. Some of the drawings are familiar from the first two books, but the science and engineering explored is different. If the reader has enjoyed the technical information in books one and two, they will find this book takes them further.