The Ripper Legacy

The Ripper Legacy is a mystery pastiche novel written by David Stuart Davies, featuring Sherlock Holmes and Dr. John Watson in a story with ties to Jack the Ripper.
Titan Books published the book in 2016, as part of its Further Adventures series, which collects a number of noted Holmesian pastiches.

Plot

A child has been abducted, yet there's no ransom note. When Holmes and Watson take up the case, they find a sinister connection to the heights of Victorian society. But just what is the missing child's connection with the infamous killings in Whitechapel?