The Unit discovers that someone has information that could expose Church while he's undercover, and so begins a deadly race against time.

The Unit fears that Church's involvement with an influential crime family may cause him to cross the line, and betray them for a life of crime.

As the Unit slowly gains information to bring about the downfall of a powerful crime family, an unexpected development threatens their progress, and forces Church to remain undercover.

As Church works to infiltrate a powerful crime family, he gets more involved than he had ever expected.

While investigating a murder, Church inadvertently becomes involved with a well known crime family.

Mac and Angie go undercover in a brothel following the murder of a second prostitute.

Stone and Angie go undercover to infiltrate a radical environmental group suspected of stealing explosives to service terrorist activities; Church must overcome a personal vendetta.

Stone and Angie go undercover to infiltrate a radical environmental group suspected of stealing explosives to service terrorist activities; Church must overcome a personal vendetta.

The Unit goes undercover to locate a prison escapee and investigate claims that police want him dead, rather than recaptured.

After being shot at a drug deal, Stone remains undercover to crack a gun dealing racket. Mackenzie is concerned about the psychological effects the shooting may have on Stone and his future as an undercover operative.

Church goes undercover with a bikie gang suspected in producing counterfeit money.

Church gives a long-term informant one last chance to prove his worth, while investigating a potential armoured car robbery.

Internal Affairs raids the Stingers warehouse after receiving a tip-off suggesting corruption.

Working undercover, Church inadvertently becomes involved in a volatile siege situation instigated by three young delinquents.

MacKenzie goes undercover to befriend a women capable of exposing a corrupt politician.

Stone goes undercover to crack a large-scale Ecstasy racket.

While undercover, Church becomes involved with Cameron Fraser, a brutal and highly skilled mercenary.

The unit goes into damage control after Kaye's disappearance.

When a serial killer claims a third victim, Undercover are called in to track him down.

When a police officer is shot, Undercover are called to investigate the prime suspects within a Romanian gang.

Church becomes implicated in murder conspiracies when he goes undercover.

When a homicide investigation into the disappearance of a teenager babysitter fails to reveal any useful evidence, Church and Angie go undercover to infiltrate a sinister criminal family.