Last year 3D TVs were all the rage. This year it’s concave 4K OLEDs. Next year your TV will probably be so advanced it’ll be too busy cooking your dinner for you to watch it. But still TV manufacturers are behind the times, because they haven’t yet managed to construct a set that can fully contain the white-hot drama of Line of Duty.

Sitting watching it you get the same feeling as when you’re placed under the x-ray machine: there’s the uneasy sensation that something incredibly powerful is being pointed at you and – good lord, shouldn’t I have a lead apron protecting my nether-parts?! – that you’re helpless to do anything other than sit still and experience it.

You may have experienced such an overwhelming feeling as you watched Lindsay Denton being waterboarded, before turning the table on her captor Prasad (Sacha Dhawan), crushing his legs with his own car and trying to kill him after extracting his confession. That really sticks in the head – innocent people tend not to attempt murder. Is Denton, a woman assaulted by every unfortunate circumstance, as innocent as we’ve been mislead to believe? Her Mona Lisa smile at the end of the episode may suggest not.

But the beauty of Line of Duty is that it sweeps across the entire spectrum of immorality, with some activities more black and white, such as the brief return of Neil Morrisey being terrific and repugnant as the terrifically repugnant DI Morton, aiding Cottan in his sliming and obfuscation. It’s a shame there’s not more of Morrisey beyond a cameo, but Line of Duty‘s world is a big dirty place, and if – what am I saying, ‘if’? – surely when a 3rd series comes along, there could be more room for Morton.

The real TV-searing heat of Series 2’s penultimate episode follows the arrest of DCC Dryden (Mark Bonnar), who’s now strung at the centre of a cobweb of evidence and unspun lies. No, wait, that’s two different metaphors in one sentence. Erm… it’s a hot cobweb. A hot cobweb of intrigue. Yes.

And it makes for a gruelling interview scene that methodically breaks Dryden’s caustic plod down until there’s nothing left for him to do but shout. His story is broken down by evidence. He moves to equivocate, only to find that move has been blocked by evidence: pictures of sexual activity with the underage Carly Kirk before her murder. He lies again, he’s outmanoeuvred again. The pressure is relentless. It’s police chess. Chess played on a hot cobweb of intrigue.

Compston, McClure, and Bonnar channel Jed Mercurio’s script to show us ensemble acting at its finest. It really is breathtaking. All the initmacy and power of the theatre but in a concrete box, on your TV screen. Give these people awards if you want, but the real proof of their talent just beamed out at you. Like x-rays.

And it sets us up for a finale that’ll likely melt your screen. You go check your TV can cope with it. I’ll go think up some better metaphors for next week. ‘Hot cobweb’ indeed…

Aired at 9pm on Wednesday 12 March 2014 on BBC Two.

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