S4E1 - Snakehead
The Undercover Unit is called in to investigate when eleven illegal immigrants are found dead inside a shipping container.
Aug. 14, 2001, midnight
S4E2 - Rich Man's World
Church uses an informant to infiltrate a drug syndicate, with tragic consequences.
Aug. 21, 2001, midnight
S4E3 - Beyond Redemption
Angie goes undercover at a halfway house to obtain evidence against a psychopathic killer.
Aug. 28, 2001, midnight
S4E4 - Tell Me You Love Me
Church and MacKenzie pose as a married couple experiencing relationship difficulties as they investigate a murder.
Sept. 11, 2001, midnight
S4E5 - Fool to Want You
Church becomes the prime suspect in a murder investigation when he moonlights as a private investigator.
Sept. 18, 2001, midnight
S4E6 - Family Values
Church goes undercover in a bikie gang to expose a major amphetamine ring, with unexpected and tragic consequences.
Sept. 25, 2001, midnight
S4E7 - Whatever It Takes
The future of the Undercover Unit looks uncertain when Stone is investigated for the shooting death of biker Chicken Lake.
Oct. 2, 2001, midnight
S4E8 - Into the Darkness
In the aftermath of Bill Hollister's murder, MacKenzie grieves while Church tries to bring the killer to justice.
Oct. 10, 2001, midnight
S4E9 - Foster Cops
Church and Danni pose as foster parents in an unusual operation to capture Australia's Most Wanted Armed Robber.
Oct. 17, 2001, midnight
S4E10 - The Whisper Room
The Undercover Unit investigates a group of paedophiles who use an internet chat-room to procure their victims.
Oct. 23, 2001, midnight
S4E11 - Feud
The Undercovers investigate an extortion attempt against a pharmaceutical company and find themselves at the centre of a long-term feud.
Oct. 24, 2001, midnight
S4E12 - One of Us
Stone is recruited by an Assistant Commissioner to assassinate the Bomb-maker responsible for Bill Hollister's death.
Oct. 30, 2001, midnight
S4E13 - Dog Eat Dog
The Undercover Unit stage an intensive investigation to nail the ex-police officer believed responsible for Bill Hollister's murder.
Oct. 31, 2001, midnight
S4E14 - Slice
Danni's cover is blown and her career is threatened when an escaped criminal seeks his revenge.
Nov. 6, 2001, midnight
S4E15 - Love Hurts
A case of mistaken identity results in Stone being recruited to assist with a major armed robbery.
Nov. 7, 2001, midnight
S4E16 - 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.
Nov. 20, 2001, midnight
S4E17 - Closure
MacKenzie investigates a Private Detective who specialises in adoption cases, with the secret hope of locating her birth mother.
Nov. 21, 2001, midnight
S4E18 - True Colours
MacKenzie makes contact with her natural mother and both women become embroiled in an Undercover operation to nail a mastermind armed robber.
Nov. 21, 2001, midnight
S4E19 - Too Many Crooks
The Unit works with an undercover operative from Queensland to defeat a gang of amphetamine dealers responsible for a kidnapping.
Nov. 27, 2001, midnight
S4E20 - Just Another Day
Stone is caught in a siege situation at a hospital when an armed robbery goes horribly wrong.
Nov. 27, 2001, midnight
S4E21 - Reunion
Church's worlds collide when he has to attend his twenty year high-school reunion as part of a drug sting.
Nov. 28, 2001, midnight
S4E22 - 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.
Nov. 28, 2001, midnight