1834. Sophia Thompson wants nothing more than to be one of the famed Bow Street Runners, London's most elite corps of detectives. Never mind that a woman has never before joined their ranks, and certainly never mind that her reclusive family has forbidden her from pursuing such an unladylike goal. She gets the chance to prove her capabilities when an urgent letter arrives from her frantic cousin Daphne, begging Sophia to come look into the suspicious death of Daphne's brother. As Sophia begins to unravel the tangled threads of the case ṣhe soon realizes that the murderer may be even closer to her family than she ever suspected.