The thrill of a whodunit comes, of course, from scouring the screen for clues and trying to spot the red herrings. Different theories emerge as we are drip-fed information. But in order for this experience to be truly satisfying, those clues must be believable, must correlate with a wider narrative. They can’t simply be plonked in along the way, otherwise the credibility of the characters is eroded. In short, if the crumbs turn out to be inedible then what, really, is the point of following the path?

The first episode of Innocent (ITV), a four-part drama from Chris Lang and Matt Arlidge that continues nightly until Thursday, was a case in point. There were so many obviously placed, flashing “telltale signs”, it soon began to feel more like an exercise in second-guessing the writers, rather than anything like a serious drama.

This was a shame because there was much else to admire. The premise was uncomplicated but potent: a man called David Collins (Lee Ingleby) had been acquitted for the murder of his wife and released from prison. If he really is innocent – and there are still plenty of reasons to suspect that he might not be – then who did murder Tara Collins?

Norris as Alice and Adrian Rawlings as Rob

The central performances were exceptional, too. I was unsettled by Ingleby’s intense portrayal of David, a broken man whose grief and regret occasionally curdled into violence. It was hard to pinpoint what was so off-putting about him – that vacant stare, or the way that he dragged angrily on a cigarette – but he just gave off a slightly unpleasant aura. Best avoided at the pub, that sort of bloke.

And Hermione Norris was excellent as Alice, David’s on-edge sister-in-law, who, with her husband Rob (Adrian Rawlins), had brought up David and Tara’s two children in the years following the murder. Alice, though, became a prime suspect after it was revealed that she and Tara had had a row on the night of Tara’s murder.

But these performances were compelling in spite of – not because of – the script, which had the characters metamorphosing almost from scene to scene, all apparently as a device to spin the viewer this way and that. David, for example, behaved in myriad different ways in this episode alone. First, he laid flowers at his wife’s grave and, with dewy eyes, hugged his brother Phil (Daniel Ryan); then we saw him banging out press-ups and threatening an old friend. Likewise, Alice’s behaviour pinballed from measured to neurotic and back again.

Rather than building psychological layers, this erratic approach gave the drama a fragmentary feel. No two scenes felt particularly connected, which struck me as a huge sacrifice to make for the sake of a few cheap tricks designed to throw us off the scent.