Watch In Deep Season 1 in Australia

Garth goes undercover as a security consultant to track down Eva Richardson, the mind behind a powerful vice ring. He uncovers a link with the drug squad and, after one of Eva's girls is discovered dead in suspicious circumstances, an internal investigation is launched with results in Liam being posted back to investigate his old drug squad colleagues. In an attempt to infiltrate the web of corruption, Garth sets up a drugs deal. But when this goes disastrously wrong, it becomes clear that someone of high rank is playing for the opposition.

The second part of a drama in which Liam and Garth investigate fellow officers suspected of collusion with a powerful vice ring. Liam's allegiances are put to the test when it becomes apparent that his old friend, senior officer Craig Griffin, is also in on the deal. Garth must race against time to find a key witness held captive by two corrupt policemen.

Liam and Garth try to crack a paedophile ring which is operating through a sophisticated website. Liam befriends the wife of the webmaster and Garth goes undercover in prison to make contact with two of the principal players. After winning their confidence, he discovers that a grisly crime is about to be committed.

Liam infiltrates a white supremacist group which has begun a systematic petrol tanker bombing campaign. Garth is assigned to provide backup and support to Liam's family, but when a vengeful man - whose imprisonment Garth was responsible for - tracks him down, he finds instead that his presence is putting them in mortal danger.

Liam discovers that the leader of the white supremacist group is not who he seems. An unwelcome visitor from Garth's past mistakes Liam's family for Garth's - and sets out to exact his revenge on the man whose evidence put him in prison.