Returning to a dark secret they all share and to a Whitechapel terrorised by an all too familiar horror, Series Five sees the show's heroes take on a serial killer with subhuman desires, but a superhuman ability to avoid being apprehended.

Series 4 begins in the summer of 1897 with Queen Victoria celebrating her diamond jubilee. Edmund Reid (Matthew Macfadyen) has left the force which gave him his career and left the neighbourhood which shaped his life. He finds himself drawn back to Whitechapel when he discovers that his old friend is set to hang for a brutal murder.

Series 3 is set in 1894. The crime-fighting team of Reid, Drake and Jackson has fallen apart, and each man gone their separate way. Drake has moved to Manchester in search of a new life and a better existence as a man of the law; Jackson has reverted back to the man Reid found hopeless in a Tenter Street brothel; and Reid has retreated deep into his own mind, policing Whitechapel with a level of obsession that leads even his chief inspector to fear for him.