Yorkshire, 1874. Annie Quaintain (Jessica Raine) is turfed out of home when her schoolmaster husband's death leaves her widowed and penniless. Shunned by society, and with no family to turn to, Annie is desperate for a place for her and her children, Martha (Amy James-Kelly) and George (Sam Bottomley), to stay. When she hears of jobs going in Culverdale Valley, where an enormous viaduct is being built, Annie, Martha and George have no choice but to set off for the promise of a new life in the vast expanse of the Yorkshire dales. Their journey takes them to a remote shanty town in the middle of a valley, the home to a community of navvies. A town called Jericho.

The cloud of Bamford is no longer hanging over the town and Coates is now in charge of Jericho. In an effort to protect its inhabitants from rogue traders, Coates makes himself some enemies, which will have grave consequences for everybody.