June 1908: Cross-dressing Dolly Butler is starting a new career as a detective with her very own Soho agency.

Her first case takes her into the brutal world of an East End plumage factory where it's not just birds that are under threat. While Dolly is off sleuthing, her adored lover, Caroline, hides from her violent husband at Dolly's home. However, when their embittered housemaid becomes aware of Dolly and Caroline's 'unnatural practices', she becomes intent on destroying their happiness. Her scheming, and Dolly's refusal to confront a friend's suspicions about Caroline's mysterious past, puts them all in grave danger.

In a page-turning, darkly comic story of obsession, self-delusion and deception, can Dolly save the woman she loves, as well as face the grisly reality of her new line of business – and the truth about herself?