York railway station, December, 1925. Detective Inspector Jim Stringer is enjoying a pint in the Parlour Bar before accompanying his wife, Lydia, to a charitable function. But when the couple meet at their regular spot near the footbridge, Jim is alarmed to see a man pointing a revolver in his direction. His thoughts go spinning back to a hot day at the end of August, when he attended the York Summer Gala in company with his boss, Superintendent Saul Weatherill, aka 'the Chief'. 

North East India, 1923. On the Night Mail to Jamalpur, a man is shot dead in a first class compartment. Detective Inspector Jim Stringer was sleeping in the next compartment along. Was he the intended target?Jim should have known that his secondment to the East Indian Railway would not be the working holiday he had hoped for. Aside from the Jamalpur shooting, someone is placing venomous snakes in the first class compartments of the railway.

1862. A goods train is speeding through the Sapperton Tunnel when it hits a makeshift pen of sheep inexplicably set up near the exit. The animals are slaughtered by the impact whilst the train hits a pile of rocks and is derailed, seriously injuring the occupants. Inspector Colbeck discovers that the shepherd and his dog are missing. Stephen Rydall who owned the sheep is shocked by the occurrence, which further affects him as he is a major shareholder in the Great Western Railway. 

1860, Wimborne, Dorset. Rebecca Tullidge, miserably married to her callous husband, is having an affair with a railway officer, John Bedloe. Much to her distress, she trips over her lover's dead body on the railway tracks. Determined to win votes for the upcoming election of mayor, Mr Feltham calls for Inspector Colbeck and Sergeant Lemming to solve the hideous crime, which takes longer than anticipated.

Halloween 1861. A special train with two carriages steams across the Lake District at night on its way to a place notorious for its record of supernatural incidents. Lighting inside the carriages is poor, and without warning, the lamp goes out in the last compartment of the second carriage, plunging it into darkness. When the special reaches the end of its journey, the passengers pour out on to the station platform. There are almost 60 of them in all, laughing and jostling. 

Following a string of successful performances along the west coast, the Moscardi Circus is travelling by train to Hexham on the Newcastle to Carlisle Railway for their next show. Yet a collision on the track causes pandemonium. When the headless body of a woman is discovered in nearby woodland, Inspector Colbeck is desperate to lend assistance, however a reluctant Superintendent Tallis forbids him from doing so. 

December 1860. Headed for the morning shift at the Swindon Locomotive Works is an army of men pouring out of terraced houses built by the GWR, a miniature town and planned community that aims to provide for its employees from cradle to grave. Unfortunately, boilersmith Frank Rodman is headed for the grave sooner than he'd expected, or he will be once his missing head is found. Colbeck, the Railway Detective, finds his investigation into Rodman's murder mired in contradictions. 

The year is 1855, and on the LNWR train to London, a criminal is being escorted to his appointment with the hangman. But the wily Jeremy Oxley, conman, thief and murderer, has one last ace up his sleeve: a beautiful and ruthless accomplice willing to do anything to save her lover, including committing cold-blooded murder... When Inspector Robert Colbeck learns that Oxley, his nemesis, has once again escaped, black memories of their shared past leave him no choice but to do his duty.

Guy Fawkes Night, 1857. Joel Heygate is the popular stationmaster at Exeter St David's railway station - an impressive figure of a man replete with frock coat and top hat, bushy eyebrows and walrus moustache. But when the charred remains of a body are discovered in the embers of the town's annual Bonfire Night celebration, everyone is horrified when it becomes clear that they belong to Mr Heygate.

East Anglia, 1861. Alone in a first-class carriage, the Swarbricks are robbed at gunpoint. But when the universally admired Swarbrick fights back, the train robber takes more than money and jewellery, killing the man working to unify East Anglia's tangle of railway networks. Inspector Colbeck is brought in from London, but as Swarbrick's glowing reputation begins to crumble, the line of investigation isn't clear.