Under Paris is part shark-thriller, part French cop movie and part Greenie parable - which is why it's getting enthusiastic thumbs-ups from unexpected quarters.
Full disclosure: when I saw the trailer for a film on Netflix called Under Paris I was intrigued. A blend of standard shark film and a police drama in modern-day Paris during a high-profile triathlon looked…. Well, as I say, intriguing.
It stars the lovely Bérénice Bejo, who made a big splash (sorry) in the 2011 French Oscar-winner The artist.
It opens strikingly enough - underneath acres of plastic rubbish in the Pacific.
Sophia heads a group of scientists tagging local sharks. One of them - they call her Lilith - turns up and kills them all - all but Sophia. Lilith used to be a common or garden-variety Mako shark. She's now a terrifying three times bigger. Something in the water, maybe?
Three years later - that was quick - a still mourning Sophia has a new job in Paris, studying sharks. This is a bit of luck. She's told that Lilith has been traced, swimming up the Seine. Not just up the Seine, but just round the corner from Sophia's Paris home.
What are the odds? You may well ask. As does the Mayor, concerned about the aquatic leg of her triathlon.
Sophia is roped in to advise - after all, she's not only a shark expert, but she's got history with Lilith the Great Big Shark. She hooks up with river policeman Adil, who is sceptical.
A shark under Paris? Sophia says cryptically "You had no question when it was a beluga and an orca." Sorry, what?
I'm grateful that Netflix offers an English language version of the trailer. This is crazy enough without anything getting lost in translation.
By now the shark squad includes the River Police, who want to shoot Lilith and a slightly irritating group of young Greenies who want to save our giant carnivorous friend. There's Sophia - I'm not sure what she wants to do - and the Mayor who refuses to believe the shark is even there.
She is of course - "under Paris", otherwise there's no movie. But there's a twist. Lilith is not alone. There's at least one daughter, pointing to a potential sequel.
The film opens on a quote from Charles Darwin - essentially "adapt or die". Perhaps the usually sequel-averse French film industry is picking up tips from people like Jerry Bruckheimer.
To which all I can say is "don't pick up tips from Jerry Bruckheimer." I'm not sure Jerry would have approved of the music underpinning Under Paris - all very Eurovision - while topside tout l'enfer is breaking out.
But by that time the number of questions being raised by this lunatic ratatouille of a movie were starting to overpower its initial entertainment value.
Isn't a shark a salt-water fish? And isn't the Seine a bit chilly for sharks? How did it get past the many locks along the Seine? How and why did it get from Hawaii to Paris anyway? Was it followingt Sophia?
And having ended the second act with a massive bloodbath, there's still half an hour to go. How do you top that? The answer - if you make it that far - will surprise you. Suffice to say: Sharks one, Paris nil.
Under Paris is beyond belief, in other words, as is the unbounded enthusiasm among several people you'd think would know better.
But of course, some people loved Snakes on a Plane.
