In July 1938, the superbly streamlined A4 Pacific class steam locomotive "Mallard" set a world speed record on the East Coast main line of 126mph, a record which still stands. Now, some 65 years on, Don Hale tells the full story of how the record came to be broken. It's a tale that goes back to the late 19th century, when the rival railway companies first began to vie with one another to set speed records between London and Scotland. It charts the technological development of the steam engine through the early decades of the 20th century into a hugely powerful and truly locomotive machine. And above all, it focuses on the singular and larger-than-life character of Sir Nigel Gresley, Mallard's designer and one of the most gifted engineers Britain has ever produced. In an account that includes interviews with surviving crew members and their relatives, the book sets the scene for the big day itself, and follows hour by hour the nailbiting attempt to break the record, as the giant "Blue Streak" thunders up the main line through the heart of England and into the record books.