Line Of Duty fans were shocked after a twist in the fourth series finale saw Balaclava Man identified as not one but several people.
Viewers gripped by the BBC1 police drama were hoping the identity of the murderer would be revealed, with almost everyone a suspect over the course of the series.
— Line of Duty (@Line_of_duty) April 30, 2017
But although Balaclava Man was shot dead by police, he was not named, and it turned out he was just working for a mysterious criminal network.
Rather than one culprit, there were “Balaclava Men, plural”.
Viewers on social media were stunned at the turn the crime series had taken.
I'm absolutely shocked!balaaclava men!this was so intense!I've never seen anything more intense! #lineofduty
— Alexandra Sch (@SandraSchillin) April 30, 2017
One fan said the episode was so stressful “I feel like I’ve just lost 5 years of my life!!”
The instalment saw the net close around DCI Roz Huntley (Thandie Newton) as her role in the death of Timothy Ifield was finally revealed.
She broke down during a gruelling interrogation, confessing as she realised the mountain of evidence against her.
But viewers are crossing their fingers that the character’s subsequent 10-year jail term does not keep her from appearing in the next series.
Let's all forget Roz murdered someone and allow her back to work next series 👍🏼 #LineofDuty
— Jamie (@jay_jay_84) April 30, 2017
— Margieandrewreichelt (@mmar219) April 30, 2017
The finale also left a cloud of suspicion hanging over Superintendent Ted Hastings (Adrian Dunbar), with many viewers suggesting he is the corrupt criminal mastermind known as H.
However, most insisted they did not want to see him unveiled as a villain.
“Genuinely thinking of starting a petition to get the writers of Line Of Duty to insure that Hastings isn’t “H”,” quipped one.
The number of viewers has grown steadily since the show moved to BBC1 this year, with 8.5 million tuning in.
The previous three series aired on BBC2, where audiences peaked at 5.6 million.
A fifth series has already been commissioned.