Where the Crawdads Sing is based on the bestselling book (by Delia Owens) that I picked up from one of those three-for-two tables at Waterstones and always thought I’d read but for some reason never did. I can’t now say the film’s not as good as the book and send everyone involved to prison, which is a pity, as that was most satisfying. (See last week’s review of Persuasion.) Still, it’s always interesting to find out what they’ve done with a book you haven’t read and, based on this, it was a lucky escape. The film is so cliché-ridden there’s a point where an entire courtroom gasps and I laughed. Not proud, but it was beyond my control. Could I send everyone involved to prison anyway? For cocking up a book I haven’t read?

Fortunately, I attended the screening with someone who had read it. She described it as ‘one up from trash, like Bridges of Madison County’ and was invaluable because there were so many narrative gaps I needed filling in even if the answer was always the same: ‘There’s a lot more on that in the book.’ So why wasn’t it in the film? No idea. This tells the story of Kya (a painfully earnest Daisy Edgar-Jones) who, abandoned as a child, has brought herself up in the swampy wilderness of North Carolina and is charged with the murder of her ex-lover. She is meant to be a creature of nature but looks, I have to say, like an Instagram influencer on her way to Zara. Or maybe Anthropologie.

The murder victim is chisel-chinned Chase (Harris Dickinson), one-time star of the school football team who had wooed Kya but then turned toxic. Every character is either good or bad with no shades in between. When Chase’s body is discovered, Kya, who has always been ostracised, is immediately accused. Represented by a kindly lawyer (David Strathairn), she recounts her life in the courtroom, while the jury gasps and we spool back in time. Much is told by voice-over, which is kind of cheating.

Kya had been fending for herself since she was a little girl. Her father was a physically abusive drunk so her mother and older siblings all walked out. Really? Your mother and brothers and sisters would leave you, a six-year-old, in the care of a violent man? I couldn’t buy it but, as I was told, ‘There’s a lot more on that in the book.’ She attends school for a day but is called ‘a swamp rat’ so never returns. Nature is her teacher along with a local boy, Tate (an especially hammy Taylor John Smith), who helps her to read and write. Eventually she becomes a best-selling author of naturalist books, which requires a suspension of disbelief the size of which you may never have encountered before.

The only adults who show Kya any concern are Jumpin’ (Sterling Macer Jnr) and Mabel (Michael Hyatt), the black couple who run a store. This is the 1950s and ’60s, so you’d imagine they’d have their own problems but here they exist solely to serve the hot white girl who is meant to be feral but always looks so crisply laundered.

All the relationships are simplistic – I had to check it wasn’t a YA novel – and it’s clunkily directed by Olivia Newman. You never feel Kya’s connection to her environment, even though I’m guessing that should be of utmost importance. For a film about what it is to be wild it’s incredibly tame. Plus you don’t even encounter any crawdads. I probably conflated crow and jackdaw in my mind so assumed they were birds but I have just looked them up. They’re crayfish! And they sing? Apparently, there’s a lot more on that in the book.