S4, EP6 "Royal Hunting Ground"
While Nick Huntley faces lengthy questioning over his role in Tim Ifield's murder, AC-12 remain convinced of Roz's involvement.
S4, EP5 "Lying Nest"
DCI Roz Huntley struggles to allay her husband's suspicions. AC-12 find a new angle to pursue their case against her.
S4, EP4 "Moral Superiority"
Nick is brought in for questioning by AC-12, but while Nick denies any involvement in Steve's attack, his suspicions about Roz mount. AC-12 discover new anomalies in the forensic evidence and issue DCI Roz Huntley with a second Reg 15 notice.
S4, EP3 "In the Trap"
As AC-12 wrestle with the new forensic evidence casting doubt over Tim Ifield, Kate is approached by another woman claiming to have been assaulted by Michael Farmer.
S4, EP2 "Who Sows the Wind"
A dismembered body is discovered, and worries grow when DCI Roz Huntley fails to report for duty. AC-12 crank up their investigation into Operation Trapdoor, concerned that Michael Farmer will go to jail for crimes he didn't commit.
S4, EP1 "In the Shadow of Truth"
DCI Roz Huntley is under intense pressure from her superiors to apprehend a serial murderer after months of fruitless investigation. When another young woman is abducted, Roz is on the scene to track down and charge a 24-year-old man.