Just when it seems the year in movies has already reached peak kid-in-the-wilderness, along comes
It's got six kids running wild. Climbing cliffs. Killing deer. Reading very grown-up books. Singing around the campfire.
But it's okay. Their dad is with them.
Or is that actually the problem?
The question that hangs over the parenting skills of Viggo Mortensen's Ben Cash, a Noam Chomsky-worshipping liberal survivalist who is home-schooling and boot-camping his brood in the forests of the Pacific Northwest, is what elevates Captain Fantastic into a rarity; a film with a nuanced central character you'll be debating the merits and ethics of long afterwards.
Is he a brilliant educator in everything from self-sufficiency to modern philosophy? Or has raising his family off-the-grid made him the leader of his own cult?
As for mom? She's not around. But she becomes the reason Cash and his brood must leave their backwoods idyll.
Yes, once Ben and his kids drive the family bus into real world, Captain Fantastic can feel like it's on a similar highway to Little Miss Sunshine, another movie which showed there's nothing like a road trip to bring family dysfunction to the boil.
The film also has a lot of fun with how the super-bright Cash kids deal with the outside world and their ordinary suburban relatives who live in it.
And there's more hilarity when the eldest, Bo (George McKay) falls in love with the first girl he meets in a trailer park while the family is heading to the kids' grandparents in New Mexico.
First-time director Matt Ross is better known for playing Gavin Belson in the tech-comedy Silicon Valley, with his movie being partly autobiographical about his own upbringing.
He's delivered a movie that might hit some soft, sentimental notes towards the end. But that doesn't stop this being a sweet, sad, funny original. One full of terrific performances, especially from McKay and the actors playing his siblings ranging in age from 7 to 18.
It's also a film gratifyingly free of pat characters. As Ben's gruff father-in-law, Frank Langella could have just been there to shout about living in the real world when his grandchildren arrive. But instead he's shown to be clearly entitled to his frustrations with the man his daughter chose to marry and the choices the couple made.
As for the man wanting a life apart for his family, who comes to realise his idealism may actually be harming them, Mortensen is, yes, fantastic in what is a career-best performance.
Ben Cash might be a deeply flawed character. But he remains fascinating throughout and Mortensen's portrayal of him is perfect.
Cast: Viggo Mortensen, Frank Langella
Director: Matt Ross
Rating: M (Offensive language, nudity, suicide, sexual references & content that may disturb)
Running time: 119 mins Verdict: Viggo Mortensen is father of the year.