Two female paramedics murdered in a month. Is it coincidence, or are they victims of a serial killer? Detective Ella Marconi isn't sure, but goes hard after her key suspects, including police officer John Morris. But each turn of the case throws up more questions and entanglements, and Ella and her partner, Detective Murray Shakespeare, struggle to find the truth among the lies. Ella also attempts to balance work and her relationship with Dr Callum McLennan, which is both growing both stronger and more difficult as they face Callum's mother's disapproval and the anniversary of his cousin's murder.
Meanwhile, Carly Martens - paramedic and close friend of the second victim - conducts her own investigation. She's certain that her fellow paramedic Tessa Kimball is hiding something, and her refusal to let it go puts her, Tessa, and even Ella into more danger than Carly could ever imagine.