WARNING: The following contains spoilers about Line of Duty: series five, episode one
Five series in and BBC juggernaut Line of Duty shows no signs of slowing down or resting on its laurels.
Tonight’s new series, which is made in Northern Ireland, started with a murderous ambush on an armed police convoy and finished with an anti-corruption officer having her throat slit and being left for dead.
For the main course viewers were treated to a textbook serve of misdirection leading up to the disclosure of the identity of the undercover cop who has infiltrated an organised crime gang and severed ties with their handler.
Steven Graham, who plays John Corbett, and Rochenda Sandall, who plays Lisa McQueen, are the new additions to the cast – both presented as apparent members of the balaclava-wearing gang who begin the episode by ambushing a police convoy transporting a seized drugs consignment.
We learn an undercover officer has infiltrated the gang, and McQueen’s reluctance to kill one of the convoy plants the seed that she must be her.
Further nervous behaviour compounds the theory that she’s undercover in the ruthless gang led by Stephen Graham – best known as Combo in This Is England – who is in terrifically menacing form.
Anti-corruption officer Maneet Bindra – who viewers of previous series will remember as the mole feeding key information to Assistant Chief Constable Hilton – re-appears and is found to be guilty of more covert goings on.
When she’s found out by anti-corruption’s dream team of DI Kate Fleming and DS Steve Arnott (Vicky McClure and Martin Compston), it leads Supt Ted Hastings – played by NI’s own Adrian Dunbar – to join the dots and declare that Hilton is the criminal mastermind known as ‘H’.
But as we’ve learnt with Line of Duty over the years, nothing is ever as it seems. Hastings himself isn’t beyond suspicion in terms of being the mysterious ‘H’.
Despite a shady side of Hastings’ persona emerging he still provides the show’s few comedic moments – tonight he asked the undercover agent’s handler, ‘do you think I came up the Lagan in a bubble?’ – a line that is likely to bamboozle audiences outside Northern Ireland.
The episode ends with Corbett, not McQueen, being revealed as the undercover officer in the crime gang, but you sense there are plenty more twists to come as AC-12 probe the undercover operation.
As soon as it emerged an undercover agent had infiltrated the gang I’d guessed it might be Corbett, given that it’s usually the person you’d least expect and viewers were given too many obvious signals that it was McQueen.
The beauty of Line of Duty is even when you’ve guessed right the revelation is delivered in such a way as to still leave you in awe.
In a final bloody scene Bindra has her throat cut after it appears she tried to double cross the crime gang.
Having set the bar so high, my only fear is that this same level of drama, suspense and plot twists is going to be very difficult to sustain over six episodes.
Let’s hope I’m wrong.