From Wilkie Collins to the adventures of Sherlock Holmes, the traditional image of the Victorian detective is male. Few people realise that women detectives successfully investigated Victorian Britain, working both with the police and for private agencies, which they sometimes managed themselves.

Sara Lodge recovers these forgotten women's lives. She also reveals the sensational role played by the fantasy female detective in Victorian melodrama and popular fiction, enthralling a public who relished the spectacle of a cross-dressing, fist-swinging heroine who got the better of love rats, burglars, and murderers alike.

How did the morally ambiguous work of real women detectives, sometimes paid to betray their fellow women, compare with the exploits of their fictional counterparts, who always save the day? Lodge's book takes us into the murky underworld of Victorian society on both sides of the Atlantic, revealing the female detective as both an unacknowledged labourer and a feminist icon.