Opening with the sleepytime of the Victorian police minister, Kerry has now appointed a new task force, Cicero, in order to find those responsible. This sees Tactical Response with a new addition to the team, Senior Sergeant Charlie Lewis - a move Lawson is not happy with as Charlie is now the TR boss.

When Shannon is attacked, she keeps it to herself, as Tactical Response continues to close in on a possible suspect in relation to the cuddle of the former police minister. Meanwhile, Leon gets a new assistant, Amber.

Shannon's career with Tactical Response is put in jeopardy after she intentionally let Lexi, the pregnant girlfriend of a cuddle suspect, escape. Kerry insists she go to see a counsellor, but what is Shannon hiding from everyone?

Best mates Lawson and Josh go up against their new boss Charlie, as well as their superior Kerry. Stella, meanwhile, helps save a journalist whose investigative reporting has put her life in danger.

After Kerry receives a passing threat, the tactical response team takes charge of her protection. She is initially dismissive of their help, but when the threats are redirected towards her son James, things get more serious.

Since Michael was fired from Tactical Response, he has been undercover, thanks to Kerry offering him the job. He sets up a drug buy meeting in order to bring the Raineys down, with Josh insisting on being the bag man. But things go wrong when the location changes at the last minute, and Michael's cover is blown.

Tactical Response goes into overdrive as they desperately try and find the whereabouts of Michael, as his undercover buy-bust went horribly wrong. His kidnapper, Liam Rainey, plays a game of cat-and-mouse with Kerry, demanding that she find his daughter and bring her to him as well as guaranteed immunity, before he'll help them get one of their own back.

While Michael remains in hospital in intensive care, the rest of the Tactical Response team are left to deal with what has happened to their colleague in their own very different ways.

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.

The Tactical Response team pull out all the stops in their pursuit of the man they believe is responsible for Michael's passing and Josh's disappearance. But the closer they get to him, the quicker he slips away from them, leaving Lawson to, literally, cross the line in order to catch him.

Ridden by the guilt of letting a fellow TR member die on his watch, Josh has gone underground, working to his own agenda and leaving the task force to pick up the pieces.

The team quickly find themselves up against a carefully planned manoeuvre as the tables are turned and those on trial hold Tactical Response hostage trying to escape from military courtroom.

Tactical Response have managed to find the ultimate dirty bomb in central Melbourne; combining radioactive material with traditional explosives. As the bomb squad work to defuse the device, Lawson, Shannon and Christian are tasked to fly to Fiji in order to extradite South Korean national Kenta Tomi back to Australia.