With Ingrid missing for seven days, the intensive police search to find her begins to lose momentum with everyone beginning to believe they're looking for a body.

Angie is undercover in an Art Gallery looking for an insider connection to a spate of robberies when a balaclava clad bandit bursts in. The gallery manager is held at gunpoint while the rest of the staff are forced into the storeroom. After being released, the prized Loxton painting is missing and an investigation ensues. Meanwhile, Harris has a copy of the Church/Ingrid sex tape in which Ingrid professionally compromises herself.

Harris attempts to teach a mate a lesson in crime and punishment, but his plan backfires with disastrous consequences. Meanwhile, news of Church's tape implicating Ingrid Burton has been leaked to the papers.

Angie meets with two brothers, who are looking for a nurse to do a mysterious job. She's amazed when she's quickly hired by the pair and has to accompany them on the job immediately. Without backup, Angie is forced to go with them or miss out entirely on knowing what they're up to.

Chris Dichiera's future is jeopardised when she's forced to shoot dead a former squat mate.

Angie, Harris and Sophie lose a colleague when a siege situation erupts at Police Headquarters.

While investigating the murder of a friend, Church loses Angie's heart to his boss, Luke Harris.

Church and Angie penetrate the liberated world of swinging couples and find that love really is a drug.

Church pushes an unstable informant to take him deeper into the drug trade, unwittingly sparking off a series of murders.

Christina's relationship with a lesbian clubber turns to tragedy when she discovers that her lover is a murderer.

When the undercover unit investigate a renegade young detective working subversively in a suburban station, they discover he has all the qualities to become the new undercover recruit.

New rookie Leo Flynn takes the undercover unit on a wild and merry dance, investigating a drug war between two rival ice cream vendors and ends up biting off more than he can chew.

Harris takes an impulsive trip to Singapore in an attempt to win Angie's heart and protect her from Internal Affairs. This plan backfires when she and her sister are taken hostage by a drug boss.

Angie's latent feelings for Church resurface when a young deaf girl arrives at PHQ declaring she's his daughter. When Harris uses her to solve a crime, all hell breaks lose.

The undercover unit simultaneously pursue a European war criminal and her drug dealing son, thwarting Harris and Angie's attempts to consummate their romance.

A sexual indiscretion of Harris' comes back to bite him on the arse when a demented bunny soldier sets her vengeful sights on Angie.

Church makes a dangerous call when faced with a conflict of loyalty between Harris and his old boss, Bernie Rocca.

Flynn endangers his life and that of his pregnant sister on a deadly assignment with two cop killers.

Chris risks her life and puts her sexuality on the line to sting a sadistic chef for murder.

Church goes undercover in a dodgy furniture removal company suspected of being a front for a drug courier business. But his affair with Ava, the former girlfriend of the owner of the company, gets the seasoned operative into a spot of trouble. Meanwhile, Constable Leo Flynn tries to make amends with Constable Chris Dichiera, whom he let down on a previous case.

Leo goes undercover in order to bust a racehorse stealing, coke dealing porn king. Meanwhile Church has a surprise meeting with prostitute Lauren Davies.

After Flynn is almost killed in a buy bust gone wrong, Church goes undercover as a spiritual medium to hoodwink an international gun runner.

Sophie takes Church to lunch with two of the state's biggest criminals. But will the meal be Church's last?

Harris is blackmailed by an adversary from his past who threatens to reveal his psychiatric disorder. Meanwhile, Angie receives a proposal of marriage.

Angie and Harris' wedding day promises to be the happiest day of their lives. There's just one minor hitch...

With Harris confined to a psychiatric hospital for ECT treatment, his nemesis, Brett Linton, abducts Angie.

Disillusioned with her new husband, Angie leaves him and transfers to Homicide.

Flynn finds himself in a treacherous love triangle when he is seduced by a colleague.

A teenage love affair involving one of the team's children puts the operatives at risk on a major drug job.

Angie faces an enormous decision regarding an aspect of her relationship with Harris and Chris' life is left in the balance when she rekindles an old relationship.

Eight months have passed since we last caught up with the Undercover Unit. Chris has pulled through and almost completed her rehabilitation. She has moved in with Leo, who has helped greatly in getting her back on her feet. She's almost ready to go back to work - until she has a startling revelation of what really happened to her on the night she was shot. Angie gives birth to a healthy baby boy. And Harris makes sure he's present at the birth.

In a race against the clock, Church goes undercover as a hitman in a desperate attempt to save a kidnapped girl.

Church's efforts to nail a high profile people smuggler are thrown into chaos by a rogue Homicide detective - hell bent on playing undercover cop.

After a wild night, Flynn wakes up in bed with a corpse, and has difficulty proving he's not the killer.

Chris becomes emotionally involved with a target who agrees to turn informant in exchange for a date with her.

Church's career is on the line when a federal police officer learns of his contrived relationship with the daughter of an illegal immigrant.

Working undercover with armed robber Damien Broadbent, a masked Leo Flynn is forced to steal the proceeds of an illegal poker game at gunpoint – and the main players happen to be none other than Peter Church and Bryan Gray. Back at PHQ, Flynn comes clean to Church and hands back part of the haul (an expensive engagement ring) on one proviso – the cops can't pressure Broadbent for their booty as it could blow his cover and put his life at risk. Church agrees, but when Anna Trukan finds the ring, she believes Church is offering his hand in marriage. Without the heart to tell her otherwise, and with Broadbent demanding that Flynn gets the ring back, Church is pulled from all sides.