Line of Duty review: It is back with more twists and turns than a cheap garden hose

When the BBC released footage of the opening scenes of the new Line of Duty series opener, you knew it meant there'd be more twists in store.

This is Jed Mercurio, after all, who offers up more twists and turns than a cheap garden hose and who is on a mission to out-write himself after the success of The Bodyguard (LOD has always been better).

Superintendent Ted Hastings (Adrian Dunbar), DS Kate Fleming (Vicky McClure) and DS Steve Arnott (Martin Compston) are back on the beat and looking for the organised crime group (OCG for those in the know) they discovered were operating at the end of the last series and who are headed up by the mysterious 'H'.

I never did trust Steps.

To know and love Line of Duty is to know and love acronyms, which I do, because words pay my wages: honestly, this programme is like listening to the alphabet being vomited up: OCG, UCO (undercover officer), AC-12 (the anti-corruption team), ED905 (the catchy name for the new case), it's like the dictionary is having a day out.

Back on the job, there's £100 million of heroin being moved from a police warehouse to an incinerator where presumably the residents living nearby never complain about the smoke from the chimneys or have any problems getting to sleep at night.

As the white van containing the drugs is taken by police convoy to its final resting place via some perplexingly quiet, isolated roads, there's an ambush involving a burning car and a plastic baby and three police officers end up dead while another is wounded but spared by the only female gang member (#MeToo).

Later, the spared officer – also a woman – is told by Fleming and Arnott that whoever had been tipped off about the convoy planned it knowing that a woman would stop for another woman in trouble. They've not met Villanelle from Killing Eve: she'd soon put them right on the matter of whether women make weaker baddies.

'Is there a UCO embedded in the OCG?' mused Fleming, who is now Steve's superior, meaning he has to call her ma'am which has prompted him to turn up his waistcoat game to 'Gareth Southgate' and grow a beard to compensate.

Later, Fleming pointed out to Hastings that the gang who ambushed the van were wearing 'dark balaclavas' as opposed to ones in jewel tones or with diamante accents.

'I didn't float up the Lagan on a bubble,' said Hastings, which probably means something or other, perhaps it's another acronym, I'll quickly make one up*.

Fleming and Arnott started looking for links but quickly found themselves facing an officer called Alison Powell who clearly knows Hastings and refused to give the trio any information other than that they had stumbled into another covert operation.

So to answer Fleming's question, yes, there is a UCO embedded in the OCG, OK?

While we tried to get to grips with the various acronyms, we were treated to a selection of snapshots into the home lives of the fab three: Fleming is back with her husband and child, or so it seems and Arnott was seen taking some painkillers which in any continuing drama is an ADDICTION KLAXON.

Hastings, meanwhile, is auditioning for Northern Ireland's Got Alan Partridge, living in a budget hotel he can't afford with a broken marriage and a broken toilet.

Let's put it this way, if Hastings is the mysterious 'H', crime most definitely doesn't This season's bad man is (dark) balaclava-toting John Corbett (Stephen Graham), who looks as if he's marginally taller than Ronnie, but a trillion times less charming and very definitely not Sorry at all.

Corbett and crew have managed to nobble Vihan Malhotra, a civilian administrator in the police who was involved in organising the processing and disposal of controlled substances – he's also PC Maneet Bindra's cousin. Ah.

In the interrogation room Hastings and cohorts discovered Maneet's links to ACC Hilton and the drugs ambush: just as we knew it would be when we'd seen Fleming cooing over Maneet's kids on a phone video, the PC's career was dead in/near the water.

Another bent copper might have decided to give it a rest, Maneet thought she'd have another pop at leaking information and went back to the OCG promising to help them in order to help her cousin at which point she discovered just how cut-throat they were. Literally.

So, farewell PC Maneet Bindra and thanks for the memories – the police force can ill afford to lose someone who can triangulate mobile phone signals with such aplomb.

Maneet was key to so many AC-12 investigations that it's hard to manage how they'll cope without her, not that they know they're without her, yet. We're one up on AC-12, people.

Meanwhile, the OCG had set up another OCG who looked like two-thirds of ZZ Top with a van-load of heroin and AC-12 had popped back to tell Alison Powell that it was time to stop playing silly beggars and tell them what was going on.

Powell told the trio that she and her team had been working on Operation Peartree for a considerable length of time and that their officer was close to a breakthrough – she then showed them who it was. Ta da! John Corbett.

Corbett is either really, really good at being undercover or he's really, really bad: but regardless, he's not been in touch with his team for five months and they can't contact him, even though Maneet managed it within about half an hour.

On one hand, Corbett has infiltrated a gang that AC-12 has been hunting for years and is collecting vital information and taking down other OCGs of interest as he does so, on the other he's overseen the murder of four police officers.

Which is it to be? I don't have a clue. And nor do you.

* Lost And Gormless After Nine: the state many LOD viewers are in as they try to keep up with the police jargon.

** Line of Duty continues on Sundays on BBC1 at 9pm.