What was supposed to be a simple surveillance of suspected drug importers, turned into a high-stakes, high-energy shoot out with gun runners. Everyone feels they could have done something to save their friend.
When the body of a young woman is found in Sydney Harbour, Inspector Julia Goodwin finally has the evidence to support her theory that a serial killer is operating in the country.
With the suspected serial killer and Blakemore's abductor, Luke, now in custody, Julia begins her interrogation. Christey is convinced by Blakemore's recount of her abduction that she was taken by two men, not just one.
A runaway yacht, a missing child and suspected multiple murders set Alex and Christey down the wrong path, where they uncover a plot to poison Sydney Harbour.
Hawker remains the professional police officer, even when he is targeted by a criminal. But when the vendetta involves his son, Hawker shows his true colours.
Christey's daughter is given a brutal introduction to the realities of police work, while the death of a girl in a hit-and-run jet-ski accident causes disturbing memories to resurface for Alex.
A discovery of a wetsuit leads to a investigation of a woman who went missing two and a half years ago and everything points to the involvement of her husband. Meanwhile love is flourishing and Gavin is getting ready for his wedding.
When the Nemesis responds to a report of gunshots being fired, Sykes and Quinn come across two teenage boys who have been injured, one fatally, after the gun they were playing with exploded in their hands.
Harry, an old fishing buddy of Alex's, appeals to her to find out what happened to his missing son-in-law, Robbo. Harry claims he has seen Robbo's ghost and is convinced that he's been murdered by his business partner.
The shooting of a woman leads to some shady operations and while protecting a witness Alex and Gavin's life are suddenly in danger. Meanwhile Gavin's wife goes into labor.