Two 14-year-olds race away from a police check-point, dragging a police officer alongside. After the chase is called off they are found on a rooftop, the plot thickens as a body is found and they become murder suspects.
Lawson, Stella and Michael respond to shots fired at a stadium where Stella is shot by the gunman. But more surprising is the fact that the gunman is Lawson's former mentor Charlie Thomas who appears to have a death wish. Elsewhere, Josh and Grace become close during the investigation of a domestic dispute.
Escaped convict Martin Gero's desperate bid for freedom sees him shoot a rookie cop before he assaults Grace as she and Josh go in pursuit of him. He then takes a female shopper and Josh hostage and the team must react quickly to avoid further disaster. Meanwhile, Stella's love life is not good and Josh buys Grace a present for her birthday.
Josh, Grace and Michael investigate a break-in at a high-security laboratory. There they find all the research animals freed from their cages except one monkey which bites Michael. He is later advised that it has a virus that is fatal to most humans. Michael must wait 20 days to see if he has contacted any of the symptoms. Meanwhile, Stella finds out that her brother, Frank, is tipping off criminals just before Stella and the team get to them. Stella must decide whether she should turn a blind eye or turn him in. Elsewhere, Josh and Grace give in to their mutual ...
Whilst Conor is away Grace stays at Josh's apartment and her car is torched outside. She realises she has no way of explaining how her car was where it was without revealing her affair with Josh. She distances herself from Josh as she tries to find out who caused the damage. Elsewhere, Michael and Stella go undercover at a huge party to recover a stolen weapon but the party erupts into a huge brawl between two rival schools in revenge for injury caused to a young man during a high-speed car chase which happened earlier.
Prominent politician Robyn Hume contacts Kerry on receipt of a DVD showing her kidnapped daughter Madision and her best friend Gemma and demanding a ransom of AUS$50,000. Gemma's father also received the DVD. Robyn asks that it be kept under wraps but what looks like a straight forward kidnapping turns into something more sinister - kidnapping for the Asian sex industry by known felon Sofia Rabowicz. Meanwhile, Kerry contacts her son James in New York - whom she has not seen for three years.
Lawson, Stella and Dom try to find out who is responsible for a series of carjackings. Josh, Grace and Michael are involved in a serious car collision whilst transporting Raelene, the mother of the men who trashed Grace's apartment and burned her car. Meanwhile, Grace's husband finds out about Grace's relationship with Josh. Elsewhere, Kerry is pulled over after being caught over the limit and Dom has a female caller.
The team try to find incendiary devices left by a crazed man at APK Media and evacuate safely its employees before time runs out. But former bomb squad member Dom senses that it's all too easy and realizes that a major bomb is left underneath the building. In trying to evacuate the car park Dom, Michael, Grace and Josh are caught up in the ensuing explosion. Meanwhile, Dom's wife Sandrine goes into labor and gives birth unknowing that Dom has been seriously injured. Josh and Grace tell each other they love one another and suddenly Grace collapses in his arms.
Whilst hospitalized Grace tells Connor that she loves Josh. Lawson and Stella deal with suicidal ex-footballer Snuffy Wells. Josh and Michael monitor a mysterious burglary attempt that leads them on a chase through a complex network of underground tunnels. Michael tells Josh he has been accepted onto Special Ops Training and is considering whether he will do it. Meanwhile, Dom undergoes an operation to relieve pressure on his brain. Then suddenly Grace has a relapse and dies. Lawson has to break the news to Josh who takes it badly. Later, Dom recovers after the ...
Lawson and the team search for Yuri, an armed man, and his son who goes on the run after seriously injuring his wife after an argument. Meanwhile, Josh goes to visit the bomber to get some answers as he struggles to keep it together after Grace's death. Elsewhere, Dom contemplates naming his new born daughter Grace and Lawson berates Leon for his radio talk during the take-down of Yuri.
Underworld leader, Bobby Lavilla, who has been living abroad is asked to be protected by the Tactical Response Team after he becomes the target of an assassination plot by his aggrieved gangland associates. Kerry and the team realise that there is an inside information leak after Bobby's decoy is shot dead whilst being transported. Subsequent unsuccessful attempts leads Kerry to work with Josh solely on an unique way to protect Bobby which doesn't win her any brownie points with Lawson. Meanwhile, tired because of not getting any sleep Dominic takes an upper from Leon...