The unlikely team of fast-track cop-on-the-rise DI Chandler (Rupert Penry-Jones) and DS Miles (Phil Davis) are back on the case, along with their uninvited amateur expert on local murder Edward Buchan (Steve Pemberton) in Whitechapel. Hot on the heels of the Jack the Ripper murders, something dark and dangerous is happening on the back streets of Whitechapel. After a spate of gruesome killings and maimings, Buchan suggests that the crimes seem to replicate those of the much-feared Kray Twins of the 1960s, powerful ganglords who once terrorised the East End of London. Are their underworld murders being painstakingly recreated? For Chandler it all points to one man but the answer is far from clear when a new set of twins appear on the scene. Decades on from the original crimes, with the danger increasing with every delay, can the Whitechapel team crack the Krays?