Season 4
Episodes
1. Snakehead
The Undercover Unit is called in to investigate when eleven illegal immigrants are found dead inside a shipping container.
2. Rich Man's World
Church uses an informant to infiltrate a drug syndicate, with tragic consequences.
3. Beyond Redemption
Angie goes undercover at a halfway house to obtain evidence against a psychopathic killer.
4. Tell Me You Love Me
Church and MacKenzie pose as a married couple experiencing relationship difficulties as they investigate a murder.
5. Fool to Want You
Church becomes the prime suspect in a murder investigation when he moonlights as a private investigator.
6. Family Values
Church goes undercover in a bikie gang to expose a major amphetamine ring, with unexpected and tragic consequences.
7. Whatever It Takes
The future of the Undercover Unit looks uncertain when Stone is investigated for the shooting death of biker Chicken Lake.
8. Into the Darkness
In the aftermath of Bill Hollister's murder, MacKenzie grieves while Church tries to bring the killer to justice.
9. Foster Cops
Church and Danni pose as foster parents in an unusual operation to capture Australia's Most Wanted Armed Robber.
10. The Whisper Room
The Undercover Unit investigates a group of paedophiles who use an internet chat-room to procure their victims.
11. Feud
The Undercovers investigate an extortion attempt against a pharmaceutical company and find themselves at the centre of a long-term feud.
12. One of Us
Stone is recruited by an Assistant Commissioner to assassinate the Bomb-maker responsible for Bill Hollister's death.
13. Dog Eat Dog
The Undercover Unit stage an intensive investigation to nail the ex-police officer believed responsible for Bill Hollister's murder.
14. Slice
Danni's cover is blown and her career is threatened when an escaped criminal seeks his revenge.
15. Love Hurts
A case of mistaken identity results in Stone being recruited to assist with a major armed robbery.
16. Psychotic Episode
Strange guns, UFOs, and piggerists with glass eyes - it's all in a day's work for Church, when his only source of information for a possible murder case is a paranoid schizophrenic.
17. Closure
MacKenzie investigates a Private Detective who specialises in adoption cases, with the secret hope of locating her birth mother.
18. True Colours
MacKenzie makes contact with her natural mother and both women become embroiled in an Undercover operation to nail a mastermind armed robber.
19. Too Many Crooks
The Unit works with an undercover operative from Queensland to defeat a gang of amphetamine dealers responsible for a kidnapping.
20. Just Another Day
Stone is caught in a siege situation at a hospital when an armed robbery goes horribly wrong.
21. Reunion
Church's worlds collide when he has to attend his twenty year high-school reunion as part of a drug sting.
22. Do the Right Thing
As Church, Danni, Stone and Angie focus on a drug sting, MacKenzie is distracted by an invitation to apply for Head of Homicide - which would mean leaving the Undercover Unit.