Tensions rise in the OCG following the events at Eastfield. With troubling questions hanging over the identity of ‘H', suspicions mount at AC-12.

Following the deadly hijack of a police convoy, AC-12 target a ruthless organised crime group known to have links with corrupt officers.

Kate and Steve attempt to track down a lead. A fresh police leak enables another audacious raid, while Steve’s attempts to gather information put him in a dangerous situation.

As the hunt for 'H' intensifies, Steve and Kate wonder if Hastings is guarding a dark secret.

Corbett's most daring plan yet requires McQueen to exploit links with corrupt police officers.

In a nail-biting 90-minute finale, Hastings's secrets are laid bare. Will 'H' be revealed at last?