George Hardy has a seemingly peaceful life in the village of Denbrook, looking after his flock of sheep and reading them murder mystery novels, blissfully ignorant that the sheep talk to each other, notably speculating on the mystery novels, all of which are invariably solved by the ewe Lily, before George reads the final chapter. But to the sheep, death is something that only happens in fiction – when a sheep dies, they believe they become clouds, as sheep can will themselves to forget things – with the exception of the ram Mopple.

One morning George is found dead outside of the trailer in the field that he called home. Once the town’s only policeman, Tim, becomes convinced that George was poisoned, the sheep are determined to investigate the death of their shepherd. But the search for the truth reveals far more to Lily than simply the truth about the death of George…

Once upon a time, I did try and read Three Bags Full by Leonie Swann, the film this book is based on. I didn’t get on with it – only read a bit, hence the lack of review – but I thought I’d give the film a go. And if you’ve read the book, there’s no harm in giving the film ago, because apart from the notion of “sheep investigating their murdered shepherd”, this is a very different story, even down to the murder method. And it’s utterly marvellous.

I’ve said before that some of the most successful mysteries are those when you don’t expect much, but when the story is revealed, you realise you are watching a fairly clued mystery after all. And Zeus be damned, that was the case here and it had me completely fooled. I went in thinking this was going to be Midsomer Murders, only with Inspector Baa-naby, only to find it was far closer to… nope, run out of sheep puns that tie into Agatha Christie or her ilk… John Dickson Baa is the best I’ve got, but this isn’t a locked field mystery.

There’s all sorts of clever going on here – things we hear that don’t quite mean what we think they mean, for example – all of which is nicely explained. It just felt like a very complete mystery. Very satisfying.

But that’s not all. Maybe it’s because I’m currently laid up with some sort of lurgy, but, damn this movie has a lot of heart. Given that most of the characters we’re following are CGI sheep, there’s no denying I was completely caught up in their stories, whether it’s as some of their beliefs are challenged, or as they choose whether or not to forget things – like George, for example, More than once, I found myself genuinely moved by certain events that I won’t spoil. And if anyone ever uses the phrase “winter lamb” to me, you’d better bring a box of Kleenex to mop the tears up…

A word on the cast – the humans are superb with a number of familiar faces, including most notably Emma Thompson, who does a good job of not stealing every scene that she’s in, and Hugh Jackman as George, giving the shepherd the warmth and heart that the role needs. The voice cast for the sheep are effective too, notably Brian Cranston, Julia Louis-Dreyfuss, Chris O’Dowd and Brett Goldstein, the latter doing dual duties as the rams Ronnie and Reggie.

One does have to question the brain transplant that Tim, the policeman, seems to gain before the final act, and also turn a blind eye to the varying sheep knowledge of the real world, but as I said, this is an absolutely marvelous film. A great mystery, funny when necessary – Ronnie and Reggie, the two rams both played by Brett Goldstein, for example – and it made me actually cry at least twice. Apparently Hugh Jackman did the same when he read the script, so I’m in very good company.