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Part 1
Chandler is now permanently stationed at Whitechapel, Fitzgerald demoted to PC with his position taken over by DC Finley Mansell. Deemed failures as a result of their inability to catch the Ripper, they are low down in the pecking order in comparison to the Organised Crime Division (OCD) run by DCI Cazenove, heralded for reducing street crime to negligible. A body is discovered in the Thames, and a series of attacks follow which echo the Kray twins' crimes of the 1960s. Despite Buchan's timely advice, Chandler suspects the local gangster Steven Dukes to be the mastermind, only to realise that he is facing a criminal duo seeking bloody revenge for the Krays' incarceration. 
Directed by: David Evans | Written by: Ben Court & Caroline Ip | Airdate: 11 October 2010

Part 2
A man is murdered at the scene of a murder by Ronnie Kray in 1966. The barmaid says the killer was Jimmy Kray. Chandler and Miles interview Angie Brooks who reveals she became pregnant with identical twins, Jimmy and Johnny Kray. Forensics will not show which twin is the killer, so they need to investigate the Krays the old fashioned way. Chandler's investigations rattle the twins and he's bundled into a car for a meeting, learning that Jimmy is clearly insane and Johnny is finding it hard to control him when he turned down their offer of backing off. The team's perseverance leads them into personal danger; Miles' son is threatened and Kent is terrorized by uniformed officers on the twins' payroll. Mansell receives a wreath delivered at his home, McCormack has a gun pointed at his head and Chandler is beaten before being dumped in Epping Forest. At rock bottom, Chandler asks for Buchan's help and takes his advice to use Jimmy's insanity to separate the twins. However, learning that Fitzgerald is on the twins' payroll, the meeting with Johnny goes awry while he and his brother rake the pub with automatic fire. Inside, Chandler spots a gun and fires back. When their ammunition is spent, the twins leave. Fitzgerald is arrested soon after while warning Chandler that he is the only one trying to stop the twins and is on borrowed time.
Directed by: David Evans | Written by: Ben Court & Caroline Ip | Airdate: 18 October 2010

Part 3
After the shooting, Chandler instructs Miles to drive to Anderson's house. While Anderson and Chandler talk, Miles becomes worried when the only person he can't reach is McCormack. Racing to his house, they find him hanging in his garden shed. Llewellyn rules that the death is a suicide. McCormack's death appears to mark the end of the inquiry, but it's all for show. The investigation moves to a secret location, Buchan's house, which will be the new incident room. Anderson can only hold the Krays off for three days and they are only too aware that they have no witnesses, no evidence and no leads. They link Ronnie Kray's liking for young boys with Jimmy Kray's 'Blonde Boy'. When the 'Blonde Boy' reveals himself as a girl, the team wonder what else is fake about these twins. Managing to obtain DNA of Ronnie and Jimmy, Chandler's group manages to confirm that their Kray twins are not related to the originals. Using this information to coax Dukes' support in exposing their organization, the Krays are arrested while it is revealed that only their mother Angie knew the truth and lied to them about Ronnie being their father. However, the Krays are assassinated while in custody with Anderson taking advantage of the resulting power vacuum within the police department. Soon after, Anderson accepts Chandler's request to set up a special team.
Directed by: David Evans | Written by: Ben Court & Caroline Ip | Airdate: 25 October 2010

Guest & Recurring cast: