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.