1893: A train carrying its passengers to the bustling industrial town of Pontypridd crashes, and in the chaos of the disaster, a killer covers the trail of a violent murder.
Two years later Thomas Chard's arrival in town to take up his post as inspector in the burgeoning police force coincides with the grisly discovery of a bodd in the River Taff. Chard grapples with the demands of his new job - rudimentary victorian police procedures, an authoritarian superintendent, and finding a murderer. His investigations lead him beyond respectable society, through the shadowy back streets of Pontypridd to the seamier side of town populated by money lenders, pick pockets, prostitutes and gamblers. As Chard's list of suspect grows, each with their own secret to guard, he realises that he must disentangle the web of lies being spun around him in order to catch a killer.