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

Church goes undercover in 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 well planned sting on a group of thieves intent on robbing a very large bank goes horribly wrong when the unit discover that the bank the group is robbing is in a completely different city... and state.

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.

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

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.

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

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. Meanwhile, Angie risks herself, and goes undercover to determine the truth about a dentist who takes advantage of his patients.

After three backpackers are murdered, Stone is sent in to investigate Evelyn Leigh, where his emotions almost cost his life.

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.

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

The undercover unit face a psychological challenge when an operative looses his identity during a long-term assignment.

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

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.

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.

Danni's life is placed in danger when a well-known career criminal turns Crown witness under unusual circumstances.

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

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

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

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

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

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