As Lawson's growing obsession with the robbery crew threatens to pull Tactical Response apart, Josh shows his leadership as TR2 assist Drug Squad with the arrest of a drug importer. But things aren't as simple as they first seem when TR discover the offender's niece has been kidnapped and held to ransom. Josh must race to save the girl, in the process meeting her mother, Tash, who will change everything.

TR score a lead when an ordinary civilian unwittingly implicates himself with Andrew Kronin's gang. As Lawson pushes the man to get to Kronin, Dom takes umbrage. Dom snaps, turning his gun on TR and flees. As TR 2 track down Dom, Lawson exults when he recovers a substantial amount of the heist money.

Stella, Shannon and Josh help to settle a violent ethnic dispute. Lawson, Michael and Christian are on the trail of a volatile young couple who are desperate to get married, and meanwhile, Josh receives a drunken phone call from teenager Minka, who is the daughter of Tash, and Kerry receives a surprise visitor.

As TR, along with the drug squad, work to catch a well known drug gang, Kerry's efforts to save Blake, a meth cook and reformed drug addict becomes personal when, devastatingly, she finds out that her son James is battling his own addiction. Meanwhile, Josh finds himself fighting for his life when an unknown man breaks into his apartment and tries to kill him.

On Shannon's first day as a Sergeant, her confidence is hurt after a juvenile delinquent steals the TR02 vehicle, however while pursing the criminal, she discovers he is easily avoidable. Tragedy strikes and Stella discovers she's pregnant.

A terrifying cyber assault on the city brings Josh and Tash together as they race against time to save the life of a badly injured woman. As the attacks increase in severity, Leon and Audrey must call on all their know how as they battle a faceless opponent who may be more than a match for them.