The Constable's Last Beat. Tales of Scotland Yard - Bianca Jenkins

Constable Wilson left the main street and turned down a side alley without warning. After a second's pause and against his better judgment, Lestrade followed, hoping he was not about to get jumped - or stabbed, or shot - either by some unknown assailant lying in wait, or by Wilson himself. Lestrade's track record when it came to side alleys and being assaulted was not particularly encouraging.

London. 1868. When a body is found dead in a back alley in London's East End, it's left to Lestrade to find the man's killer, a task made more difficult by the fact that the murdered man was one of their own - a constable with Scotland Yard!