Mary Helena Fortune (1833 - 1911) was born in Belfast and emigrated to Australia, where she became one of the earliest and most prolific women writers of detective and crime fiction. Writing pseudonymously as Waif Wander and as W. W., she published hundreds of stories, many of them serialised under the collective title The Detective's Album in The Australian Journal between 1868 and 1908.

Her stories range across detective fiction, Gothic horror, melodrama, social realism and proto-noir, and are marked by an unsparing portrayal of colonial society, the goldfields and urban Melbourne, including the prevalence of violence and the mistreatment of women.

Although primarily a crime writer, Fortune regularly used supernatural and uncanny devices - ghosts, revenants, ominous visions, phantom vehicles and the return of the dead - and her relevance to speculative fiction lies at the border between Gothic fiction, crime fiction and the fantastic.