When the body of a young man is found in a beachfront apartment in Bondi, Detectives Tori Lustigman and Nick Manning are assigned the case. Is this brutal murder a domestic, a robbery gone wrong or something far more sinister?As other ritualistic murders occur, they discover the killer is using a social networking app to entice his victims. Anyone using the app is now at risk, and it's a race against the clock to catch the serial killer before he strikes again.With mounting evidence to suggest the perpetrator has killed before, Tori and Nick start digging through old investigations. The discovery is shocking. They uncover up to 80 possible murders of men that took place in the 80s and 90s in NSW - unexplained deaths, ‘suicides' and disappearances. Haunted by the disappearance of her teenage brother, Tori's fascination with the case soon turns to fixation.As they investigate past crimes, they become convinced that the current killer is somehow connected. In reopening the cold cases the detectives reveal the hidden truth about the past murders and uncover critical evidence leading to the killer. In doing so they finally give closure to the victims' families bybringing the killers, both past and present, to justice.