A pea-souper Lincolnshire fog descends and transport networks are disrupted. Ruby Grummett, a railway crossing-keeper, erroneously believes the Skegness train has been cancelled and opens the gates to allow a council lorry to pass through seconds before a massive black engine comes hurtling out of the murk. The lorry driver is killed as the train derails and spins Ruby’s tied cottage on its foundations. Trying to establish whether a crime has taken place, DI Yates and his team search through the ruins and unearth some macabre remains. The accident site becomes a crime scene. The simultaneous reopening of a cold case investigation into the disappearance of an au pair many years before seems to be unrelated until some schoolgirls vanish. They have almost certainly been abducted.