When three police officers are shot dead during the hijack of a seized drugs transport, AC-12 move in to investigate possible police collusion.

A fresh police leak enables another audacious raid, while Arnott's attempts to gather information put him in a dangerous situation.

Corbett's most daring plan yet requires McQueen to exploit links with corrupt police officers. Meanwhile, the AC-12 team make a shocking discovery.

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

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

The search for the mysterious H reaches its climax as long-buried secrets finally come to light.