London, winter 1892. As he can now only walk with the help of a cane, Inspector Henry Wilkes has been reduced to tracking dog killers in the tunnels of the Underground. Billy Bennett, a street urchin, is his assistant.

When Alice Pickman, a young lady of good family, asks him to reopen the inquiry into the death of her sister, Wilkes unwittingly enters a minefield. As a worthy heir to Sherlock Holmes, he seeks to dissipate the fog that envelopes the city of Jack the Ripper, the mist that is a heady mix of coal, lies and perversion.

Especially as the body of a girl, found with her head smashed open in an underground passage, will link the two cases.