Michael has been a busy man since being fired from Tactical Response. Thanks to the squad's head honcho Kerry he's now undercover, and his job is to bring down the Raineys, a family team of cocaine importers. He sets up a buy-bust meeting in order to bring the Raineys down and coaxes Josh into becoming his wingman. The trade-off location changes at the last minute and whilst TR catches some of those responsible. Col Rainey has taken Michael and gone underground. Has his desire to prove himself to everyone put his life in serious danger? Meanwhile, Shannon finds herself face-to-face with her attacker.

The Tactical Response team continue their search for the man they believe is responsible for both the Police Minister and Michael's murders, as well as Josh's possible disappearance. They find out that he steals identities off people as a means of not being caught out, and Lawson has to make a big decision in order to catch him.

After the assassination of the Victorian police minister, Kerry appoints a new task force, Cicero, in order to find those responsible. How will Lawson and the team react to new boss, Charlie Lewis?

Senior Constable Michael Sandrelli remains in intensive care whilst Tactical Response are left to pick up the pieces. Meanwhile, Shannon lets her emotional guard down.

As the bomb squad work to defuse a bomb, the team are tasked to fly to Fiji to extradite a South Korean National back to Australia. Shannon also responds to Lawson's marriage proposal, sort of.

Headstrong Kerry is dismissive of her own safety but when the threats are redirected to her son, her anger at the perpetrators can't be contained.

Tactical Response goes into overdrive as they desperately try and to locate Michael after his undercover buy-bust goes horribly wrong. Josh starts to crumble under the guilt of letting Michael get away while Stella is furious, realising her best friend, and once lover, may not come back alive. It's a race against time as Kerry fights political red tape and the remaining members of Tactical Response do anything they can to get one of their team back safely.

With a renegade Josh risking everything to find Michael's killer, the team finds themselves chasing one of their own and are forced to confront the question of how far they'll have to go to stop him.

Tragedy can have a profound effect on those involved. Everyone has different coping mechanisms, and Tactical Response continues to reel from a tragedy within their own ranks. Stella can barely build up strength to face the day and Christian appreciates a comforting presence from Amber. Josh, feeling responsible and immense guilt from what has happened, goes underground, deliberately avoiding contact from anyone at TR.

Tactical Response find themselves up against a carefully planned manoeuvre when Lawson and others are taken hostage by the Cuckoo as part of an escape attempt from a military courtroom. As part of the team negotiates for Lawson’s freedom, Josh and Stella follow their own investigation: searching for a bomb.

Shannon struggles to overcome the impact of a personal crisis, and must face her demons in order to save a woman’s life.

Lawson challenges Charlie’s authority to pursue his own agenda with the Marauder bikies while the rest of the team protect a journalist under threat.

The assassination of the Police Minister and a war brewing on the docks throws TR into the centre of a major new task force investigation. Secondly, Shannon keeps a shocking secret from Lawson and the team during an assignment to protect a woman...

When a group of students are lured into being drug mules, TR races to stop them, as Kerry warns Lawson he risks compromising a federal investigation.

After rescuing two children, Josh's rage spills onto their father, who may have attempted to kill them. The new inspector challenges Josh's position on the team

Lawson and Grace try to talk-down a troubled teenager when she threatens suicide, trapped on a rooftop with her young boyfriend. She was later found to have killed her boyfriend's father. Grace's inexperience is quickly revealed when she tries to fix the situation, which ends in the young woman's tragic death.

The TRG is called out to a sports oval where a heavily-armed gunman shoots Stella, who is saved by her kevlar vest. When the gunman requests to meet with a senior officer, Lawson approaches him and finds he was actually a former weapons-master who intends on suicide-by-cop. The situation ends when, after trying to avoid shooting the man, Lawson is forced to shoot and kill the man when he pulls a handgun on him.

A criminal in custody escapes from the prison van he is being tranported in, and makes an audacious break for freedom. In doing so, he assaults Grace and takes a woman hostage. He then forces Josh to drive him around town before playing a little Russian Roulette. However, Josh is saved and the criminal is arrested

When the TR team intercepts a known drug dealer, they discover that a robbery is about to take place, which then turns into a siege when the robbers take hostages. One of the criminals falls into a basement beneath the bar and later dies. Dom goes in to try to convince the robbers to stop, but the owner of the bar is shot by a spear gun. Eventually, one of the criminals gives up while the other is arrested

Josh, Grace and Michael investigate when an alarm is going off at a high-security laboratory. They find that an animal rights activists group calling themselves 'Freedom From Torture' has freed almost all of the research animals from their cages. Michael is bitten by a monkey who is later found to have herpes

Michael is found cleared of the herpes. The team arrives at a big surburban party and find a group of teenagers have stolen a gun from a security guard. Stella and Michael then go undercover to try and retrieve the stolen weapon. Michael then saves a high school boy from being severely beaten by kids from a rival high school

When a politician’s daughter and her school friend are kidnapped, the team is asked to run a covert operation to get the girls back safely. After it goes wrong, the team discovers the daughter and her friend set the ransom up, before they need to be saved from a lying con-artist.

Lawson is a part of a high speed chase involving a group of carjackers, Kerry is pulled over for drunk driving, and Josh, Grace and Michael are involved in a fatal car accident.

TR is called to a media centre, where a man has locked himself in a room and has planted a number of paint bombs throughout the building. Michael is hit, but not injured. Dom discovers where the bombs really are, and him and grace are both hospitalised after the explosions.

Lawson and Stella deal with a suicidal ex-footballer, Michael and Josh chase burglars through a series of complex tunnels, and Kerry is kept busy at the hospital where Dom and Grace are recovering. Grace unfortunately dies abruptly, while Connor confronts Josh after Grace revealed to him she was cheating on him with Josh.