On a searing summer's day paramedic Holly Garland rushes to an emergency to find a man collapsed with a bullet wound in the back of his head, CPR being performed by two bystanders, and her long-estranged brother Seth watching it all unfold. Seth claims to be the dying man's best friend, but Holly knows better than to believe anything he says and fears that his re-appearance will reveal the bleak secrets of her past-secrets which both her fiance Fraser and her colleagues have no idea exist, and which if exposed could cause her to lose everything. Detective Ella Marconi suspects Seth too, but she's also sure the dead man's wife is lying, and the deceased's boss seems just too helpful. But then a shocking double homicide related to the case makes Ella realise that her investigations are getting closer to the killer, but also increasing the risk of an even higher body count.