Phryne investigates the death of a young female worker in a factory ‘accident’ and soon learns that the woman’s death might not be the misadventure the police think it is. Faced with a wall of secrecy and lies, Phryne sends her trusty maid, Dot, undercover into the factory to investigate. When a second suspicious death occurs, Phryne fights desperately to save one of her closest friends from the gallows.