Spring 1858 The route of the Caledonian Railway through the Scottish countryside is disrupted by a fatal crash The Railway Detective Inspector Robert Colbeck & his trusty Sergeant Victor Leeming are called from London to investigate & must contend with old enemy Superintendent Rory Mc Turk to uncover the criminals behind the disaster The motive for the crash is unclear with suspects including the North British Railway a group of sabbatarians & those with personal vendettas to pursue Can Colbeck & Leeming crack the case before the Royal family makes their train journey to Balmoral?