As a nearly full-fledged member of the Agency, the all-female detective unit based in Miss Scrimshaw's Academy for Girls, Mary Quinn, disguised as a poor apprentice builder, must brave the sinister underworld of Victorian London in order to unmask a murderer.

Second in a three volume series. "The second outing with a daring young detective."--Jacket, inside front flap. Novel. Includes an excerpt from 'The Agency: A spy in the house'.