A young woman is discovered brutally murdered in the fashion of Jack the Ripper. Chief Inspector Frederick Abberline believes The Ripper has returned, but Reid, the new head of the precinct, believes a different kind of evil may be at work.

When a toy-maker is murdered, a 14-year-old boy is the suspect but Reid digs deeper and discovers a vicious child gang and its brutal master. Jackson's gambling may expose his American past.

Deliberate contamination is suspected in a sudden cholera outbreak . Emily's search for a charity patron proves difficult.

The brutal clearing of a local slum for the underground railway reveals an almost indecipherable murder scene and an unreliable slum girl witness. Lucy Eames, beautiful and disturbed, is the unlikely key to a Byzantine web of conspiracy.

A string of brilliantly masterminded robberies keeps Reid and his team busy and leads to a blast from the past for Drake when he is confronted by his former army colonel. As the net closes in on the robbers, the sergeant finds his loyalties put to the test.

International haulage tycoon TP Swift arrives in town to acquire an ailing shipping line, accompanied by a team of private detectives, who proceed to cut a violent swathe through the borough on a mission of vengeance. As Reid focuses on the murder of an engine inventor, Jackson and Susan's past comes back to haunt them, bringing their future in Whitechapel - and their very lives - into question.

Reid is adrift, his team in pieces and Leman Street shaken to its foundations following recent events. A kidnapping offers him cause to assemble his men and tackle the white slavery ring operating in their midst. But Reid is gripped by a growing obsession that this leads back to the terrible secret from his own past.