In Season 3, Eliza finds herself investigating more fresh and surprising mysteries, ranging from a disappearing magician to police corruption, as she struggles to build her detective agency. Growing competition from a rival agency creates new problems, and all the while she is still juggling her relationship with Inspector William Wellington, the Duke.

A famous magician does the ultimate disappearing act and vanishes into thin air. All of London is talking about the mystery and Eliza is hired by a newspaper to investigate, despite the fact that Duke is already on the case.