Spoiler alert: I don’t want spoilers, thanks

Picture: BBC/World Productions

We have reached Hump Day, the figurative midpoint of the week. Once this would be the point of reflection that just two more working days remained before the weekend, but Wednesdays are now beset by another anxiety: it’s four days until the next instalment of Line Of Duty.

The series has been slow to get off the ground, a deliberate ploy by Jed Mercurio to hook viewers into a longer, seven-episode run, but in last Sunday’s fourth episode of Series 6, we had a proper LoD corker. In-prison murders, bent coppers everywhere, a set-piece gun battle that matched the bank heist in Heat for loudness, and a boo-the-villain moment between shadier-than-shady Deputy Chief Constable Andrea Wise and Ted Hastings. Here you can’t help weighing up whether Wise will be uncovered as a so-called ‘H’, or even if she’s bent at all. Given the number of corrupt senior officers in this constabulary, it feels like most executive ranks are working for the OCG. But for now we’ll have to make do with the figurative moustache-twirling from Wise as she makes knowing glances at a clearly exasperated Ted.                                                                                                                                                                   

Thankfully, now we know that Hastings isn’t the elusive fourth H. Actor Adrian Dunbar confirmed to Elizabeth Day's How To Fail podcast that it's definitely not him, to his relief. “I spent all this time playing this character and I always thought Ted had a sense of duty and a moral core," he explained, revealing that Jed Mercurio had told him that he wasn’t the show’s arch villain. Dunbar says that he’d have found it hard to accept Ted was a baddie: “Jed is aware of our audience and they know Ted has a sense of moral fortitude,” he told the podcast. “I am glad he came out of it with flying colours."

As Sunday’s viewers will have seen, nasty Wise is pensioning Hastings off and, in a beautiful play on corporate politics, merging AC-12 with two of the force’s other anti-corruption units. Given how much the OCG has got its fingers into City Police, you wonder if all these units are doing any good at all. This, then, coincides with the BBC’s latest tease, news that Episode 5 will feature hard-faced AC-3 boss Patricia Carmichael, who appeared to put herself in the frame to be an H in Series 5 when she was brought in to investigate Ted. She is another wonderful panto villain, and given that she presided over an interrogation infiltrated by a murdering junior, not entirely beyond suspicion, either.

Picture: Instagram/Line Of Duty

Twitter and all the rest is beside itself with speculation since the latest episode, which ended with one of Hastings’ trademark “Mother of God!” exclamations as he read a report DNA-linking Series 6 chief baddie DCI Jo Davidson with someone already known to him. Brilliantly, Mercurio left the identity hanging. A BBC website accidentally posted a picture of a big name to come into the cast this weekend, before quickly taking it down, sending the Internet into meltdown in speculation as to who it was. I don’t want to know. I don’t want spoilers, thank you. I want to play the game at home each Sunday night, knowing that it’ll be another seven days before more is revealed, and not until. This is the kind of suspense-generation you used to get with Doctor Who in the old days. Except here, the production values are in another league entirely. 

Crucially, it’s got the nation talking, when not frantically trying to book haircuts and pub garden tables. Mercurio is just an almighty tease, but the way he plays with the audience is almost psychotic. Conventional set-up would have the villain revealed in Episode 1 and the procedural performed before the big reveal at the end. But not with this show. Villains are suggested, rather than confirmed, OCG sleepers could lurk at every turn. The suspicious looks half the cast spend each episode giving each other are nothing compared with what we viewers are dishing out. Such is Mercurio’s mind that none of the cast are without doubts. For all the clear baddies (such as former teenage delinquent-turned rookie copper - inexplicably, given vetting techniques - Ryan Pilkington) you just know others are hiding in plain sight. The guessing game is half the fun, though not good for blood pressure, as you weigh up all the possibilities. Given how many senior officers in this force are at the very least suspect, Line Of Duty is very adept at recycling supporting characters that turn up like bad pennies in elevated positions. Thus you’ve had the inexplicably over-promoted div Ian Buckells, plus Arnott’s dodgy boss from Series 1 who is now the chief constable, and a number of ad hoc promotions from sergeants to inspectors. Clearly, City Police is where you can see your career advance. Makes you wonder why...

That, then, cruelly, is how it is. Mercurio might reveal more in Episode 5, or he may hold it back until 7. Such is his thinking, he won’t follow convention at all. Columbo was always predictable, in that you knew the dishevelled detective would crack the case in the final minutes with his “Oh, just one more thing...” disarmament of the chief suspect. Line Of Duty won’t do that. While it’s unlikely that Mercurio won’t abandon the moral core of the show that Dunbar talked of, and its more than likely that Steve Arnott and Kate Fleming will solve the whole thing and, possibly come to Ted’s rescue (because even Line Of Duty should uphold some conventions of television), there really is no guarantee that they will. Brilliant television by any stretch.