Gang warfare is raging in the East End. Wisbech sends Strauss and Mabel undercover, whilst Rabbit finds himself ostracised from the case due to his age.
Rabbit, Strauss and Mabel are on the case of a mysterious killer who takes the guise of the Brick Man, a mythical figure from London folklore. And Lydia emerges from the shadows with designs on Mabel.
D.I. Rabbit's been chasing Victorian London's criminals for as long as he can remember but he's not as young as he was and his heart keeps stopping at inopportune moments so he is given a fresh faced assistant straight out of university.