In 1974, a 17-year-old girl in Sydney answered the door to a man claiming to be an encyclopaedia salesman who carried nothing with him and left her with a chilling "full body rush" of fear.

Decades later, that woman's daughter - award-winning author Candice Fox - realised this family story aligned with the timeline of two unsolved homicides from the same neighbourhood. Candice details how this personal connection led her to report the encounter to police and attempt her own investigation into the deaths of Lynette White and Maria Smith and how these tragedies formed the inspiration for her new novel.