The Mangle Street Murders - M. R. C. Kasasian

After her father dies, March Middleton has to move to London to live with her guardian, Sidney Grice, the country's most famous private detective. It is 1882 and London is at its murkiest yet most vibrant, wealthiest yet most poverty-stricken. No sooner does March arrive than a case presents itself: a young woman has been brutally murdered, and her husband is the only suspect. The victim's mother is convinced of her son-in-law's innocence, and March is so touched by her pleas she offers to cover Sidney's fee herself. The investigations lead the pair to the darkest alleys of the East End: every twist leads Sidney Grice to think his client is guilty; but March is convinced that he is innocent. Around them London reeks with the stench of poverty and gossip, the case threatens to boil over into civil unrest and Sidney Grice finds his reputation is not the only thing in mortal danger.