Reid must return to Whitechapel to covertly re-investigate a case made by Drake and Jackson.

Reid struggles to adapt on his first day back at H Division under Drake’s command.

Jackson feels the heat when a double murder throws light upon his recent illicit activities.

When a footballer is brutally murdered, a key suspect is a man close to Drake's heart.

Drake's life unravels as he questions whether he sent an innocent man to the gallows.

The walls close in on Reid as a secret from his past threatens to destroy his future in Whitechapel.

The walls close in on Reid as a secret from his past threatens to destroy his future in Whitechapel.

Reid and Long Susan are set on a collision course after a locomotive disaster.

A curiosity shop is the scene of a murder, with signs of a secret dungeon and a girl held captive.

Alex le Shayne, a mysterious clairvoyant is found dead at the local performance place. Jackson presumes poison has a part to play. As Reid is missing Drake steps in to investigate. Elsewhere Susan continues to care for Mathilda and plans to send her to Switzerland.

Ghosts of Whitechapel's past come alive, setting our heroes on a path of destruction.

A destructive gang of youths unleash hell upon the streets, but it's not until daylight breaks that the true horror of their brutal work is revealed. The trail leads the team of H Division into the heartland of one of the city's oldest trades - the London Breweries - where conflicted loyalties reign, and grief and anger create a potent concoction.

The recovering Reid finds the unconscious Lady Vera Montacute in Whitechapel next to the corpse of a flower seller.

The murder of a chemist lifts the lid on a backstreet abortion racket.

When an American journalist is killed in Whitechapel, his story threatens the peace.

Jack the Ripper may be fading into memory, but east London has found no peace. An investigation into the assault of a policeman leads DI Reid and the men of H-Division to the newly-emergent Chinatown, where Jackson discovers evidence of a new and devastatingly powerful opiate. Reid fears a new kind of hell is to be released onto his streets.

A young woman is found murdered at the London Hospital and the only clue to her identity is an unusual deformity. The hunt for her killer takes Reid and the team into the shadowy netherworld of the freakshows, where they must seek the help of Joseph Merrick, aka the Elephant Man. Reinforcements for H-Division arrive in the form of DC Albert Flight.

The abduction of a prominent member of the London County Council introduces Reid to Councilor Jane Cobden, the first woman appointed to the LCC - because it appears the kidnappers are radical supporters of Cobden's aims. Long Susan is taken by force to the gang's hideout, and she soon finds herself growing sympathetic to her captors' lives and aims.

An Irish bomber is sprung from prison and barely a day later a prominent opponent of the Home Rule movement is murdered. Chief Inspector Abberline is convinced that the Irish Republican Brotherhood is active once more and orders Reid to send the Irish DC Flight undercover into Whitechapel's Irish community.

An investigation into the brutal murder of a Telegraph Boy reveal a vice racket being run from the offices of the GPO. A ledger leads Reid to the centre of the one of London’s most august financial institutions, Barings Bank.

Churches and synagogues are being burnt and desecrated in Whitechapel and Reid suspects the same hand behind the various attacks. Meanwhile, the all-too-brief domestic happiness that Sergeant Drake has enjoyed is disrupted by the arrival of a friend from his wife Bella's past, the mysterious and charismatic scholar, Gabriel Cain.

A valuable symbol of the British Empire’s wealth shows up in the form of an uncut diamond. It is a jewel ‘freed’ from the diamond monopoly of De Graal by one Daniel Judge, Captain Jackson’s untrustworthy older brother. Reid and Flight find themselves being drawn to the plight of a local craftsman defrauded of his work and income by a scam that is set to return H Division to the malign influence of Detective Inspector Jedediah Shine.

Death and violence comes to Whitechapel once again. Some decayed and murdered bodies are discovered in a slum tenement, and the advanced stages of the police divisional boxing championship reveals the vengeful ferocity to be seen within the ranks of the police force.

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.

As the dock strike of August '89 takes hold of the city, the killing of a Jewish anarchist leads Reid and the team into the heartless chicanery of the British government's fight against distant empires and global terrorism.

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.

Plot of this episode is not specified yet. Please check back later for more update.

Plot of this episode is not specified yet. Please check back later for more update.

All you need to know ahead of series 4 as Whitechapel's finest return to the lawless streets of London.