Warning: This column contains Line of Duty spoilers

And breathe...After seven Sunday evenings spent on the edge of our sofas, the identity of Line of Duty’s final H has finally been revealed.

Almost 13 million of us tuned in to discover that The Fourth Man, the remaining corrupt police officer, had been right there under our and AC-12's noses all along, right back since series one.

Hiding in plain sight, it was none other than – Mother of God - DSU Ian Buckells in cahoots with the organised crime group (OCG). Bumbling Buckells.

For weeks the internet has been awash with all manner of wild theories, but it turns out that us armchair sleuths – including Jenny from Gogglebox who was literally taking notes – had been overthinking it.

Buckells had golf clubs in his office, but surely it wouldn’t be that obvious he was a caddy? Would it?

And what was it that rumbled him? His spelling (and some fantastic detective work from AC-12's newest recruit DC Chloe Bishop).

To quote our hero, Superintendent Ted Hastings (like the battle), this sixth series of Jed Mercurio’s labyrinthine police procedural had really been “sucking diesel”.

But it’s ’definately’ fair to say that a sizeable proportion of people with a Twitter account felt Sunday night’s season finale, which could be the last ever episode, ran out of fuel.

To re-cap, the series started with Hastings’ team looking into this series' antagonist DI Joanne Davidson (the brilliant Kelly Macdonald) and the failure of Operation Lighthouse to identify the killer of journalist Gail Vella. Plus, AC-12 trio Ted, Steve Arnott and Kate Fleming were battling their own demons.

From there Mercurio served up Line of Duty’s signature adrenaline-fuelled mix of shock deaths, twists, ill-advised convoys, tense interviews, ‘Jed’ herrings, baffling abbreviations (new for this series, the CHIS, or covert human information source) and proper boo hiss villains in the shape of Ryan Pilkington and Patricia Carmichael.

This latest series has been one of those telly events which brings everyone together – something that has become increasingly rare since the advent of streaming services such as Netflix, which encourage viewers to binge whole series in a couple of greedy sittings.

But at 9pm on a Sunday for the last seven weeks there’s been an appointment to view – and because it was rationed on iPlayer, rather than the whole series dropping at once, we’ve been watching in sync.

Those shared experiences have felt more precious than ever having spent more than a year in some form of lockdown and unable to connect with others in the ways that we usually would.

Surely the reward of seven weeks of dedicated viewing would be a big shock reveal about H’s identity and a satisfyingly nail-biting interview showdown in the famous ‘glass box’? Maybe there be an ‘urgent exit required’ and a getaway.

Instead we got a grumpy Brummie bloke in a prison issue tracksuit.

For many the last episode felt underwhelming.

Ted spoke for many of us when he lamented: “All the time we were here, thinking we were chasing some criminal mastermind, but no... Your corruption was mistaken for incompetence.”

“Yeah right, I’m a blundering fool. I’m only the one who’s made total mugs out of you lot,” Buckells shot back.

There was some closure, though.

Gail Vella’s murder was solved and the investigation into the OCG-related murder of Lawrence Christopher, which Vella was looking into (originally botched by a team which included Buckells) was re-opened with a suspect in the frame.

Joanne Davidson went into witness protection and got new life in what looked like a Boden catalogue.

And it was genuinely heart-warming that Terry Boyle, taken advantage of by the OCG right from series one, finally got a safe and happy home.

My overwhelming emotion was actually relief.

The tagline for this series was lies cost lives, and all series long I’ve been nervous that one of Ted, Kate or Steve might not make it to the end.

Because, as we know by now, with Jed Mercurio anything is possible.

But there were still a couple of big questions remaining: firstly, was that really it?

There’s been no word yet about series seven.

The suspects’ mugshots have all been taken down from AC-12's pinboard and put away in a box, Ted is being retired and Patricia Carmichael is taking over as head of anti-corruption.

So could this be the end of the line or will there be a new story arc?

And, secondly, what will fill the Line of Duty shaped-hole in my life?

After Sunday at least that one is easily answered – I'm going to go right back to the beginning of the first series and see what clues I missed the first time round.