Mackenzie and Angie face an Internal Affairs investigation when an informant suicides, while Stone faces some important issues about his future in undercover.

The Undercover Unit are assigned to investigate a five-year-old unsolved bank robbery with tragic consequences.

A personal favour from Church becomes a case for Undercover when an illegal organ-trading scam is exposed.

Church must put his career on the line when an old Academy buddy is implicated in a homicide.

Angie is stalked by an obsessed admirer as she works undercover to expose an armed robbery ring.

Mackenzie's past comes back to haunt her when her adopted brother is released from prison.

Danni and the rest of the UCs are called in when a well-known career criminal turns Crown witness under unusual circumstances.

Mackenzie faces a dilemma when Detective Inspector Bill Hollister is revealed as a regular client at an illegal brothel which is the subject of a sting.

Danni learns the meaning of betrayal when she is forced to use an innocent person to solve a murder.

When Church strikes up an unlikely friendship with a hitman, after preventing him from killing himself, he is drawn into the middle of a heated triangle with no simple solution.

The team struggle with Carl's choice, as they remember him through counseling sessions. His final moments you'll never forget.

When Church conducts a sting on a bikie gang, a simple gun deal becomes complicated when Church is hired to do a hit.

Mac and Church must infiltrate a neighbourhood residents group who are protesting the acquittal and return to the neighbourhood of a local teacher recently charged with the murder of a young student.

After three backpackers are murdered, Stone is sent into a hostel to investigate Evelyn Leigh, where his emotions nearly cost him his life. The death of Church's father gives him the opportunity to reflect on their relationship.

Church becomes involved in a young boy's life after he catches him trying to steal his car, and uses him to uncover a car stealing racket.

In court, things go horribly wrong when the Magistrate dismisses the charges against Tony Howarth for shooting Bernie Rocca.

Hollister asks Mac for help to capture the elusive Marty Stockwell, a master bank robber. He fatally shot one of Hollister's men, and now he wants revenge. So, Church and Danni go undercover to try and bring him to justice.

Danni's future with the unit is on the line when her ex-boyfriend becomes the prime suspect in a horse-doping scam

Angie's assignment is jeopardised with the unexpected arrival of her sister; and Mac is faced with a dilemma when she discovers that Danni's involved with an associate of an underworld heavy.

A well-planned sting goes horribly wrong when Church infiltrates a criminal gang who are intent on robbing a very large bank. Following the operation, Mackenzie makes a decision to visit her parents.

Church goes undercover into the world of stolen art and must grapple with some of the conflicting emotions which have shaped his character and behaviour when he discovers that the target abuses his son.

A sassy new operative arrives at the unit just as the group go undercover to entrap a group of young thieves. But a mistake leads to a kidnapping, placing everyone in danger.