During the 1830s, children worked 12-hour shifts in the mills, and the new class of mill-owning families prospered. A third of the workforce at Quarry Bank are apprentices, sold by different workhouses to the Greg family. The apprentices have no choice but to work at the mill until they reach adulthood.

Esther Price shows up at at court in Manchester after having assaulted her overseer, Charlie Crout. Apprentice house manager Mr Timperley has been sent to the workhouse in Liverpool to collect a replacement apprentice and comes back two sisters called Lucy and Catherine Garner.

Esther and Lucy make their towards Liverpool, followed by Timperley. They find out that Lucy's sister never returned to the workhouse, while the apprentices are shown political activist John Doherty's pamphlet. Robert discovers who the father of Susannah's child is and arranges to move her to another mill.

Lucy and Esther believe that Mr Timperley is responsible for Catherine's disappearance and become determined to expose him but are blocked every time they try. Esther's sister Martha discovers one of the notes Esther left there and travels to Quarry Bank Mill hoping to find her.

Four years on from the Poor Law Amendment Act, impoverished economic migrants from the south of England start to arrive at Quarry Bank Mill. The appearance of John and Rebecca Howlett with their children Jack and Timothy, and Will Whittaker and his grandfather Abe, causes unease in Styal village as the mill workers worry that these desperately poor families will drive down everyone's wages.

Esther leaves the apprentice house after signing her contract of employment. Her new home is a small, dirty cellar in Styal village, but it gives her some freedom. Patience makes the younger girls' lives a misery following Esther's departure.