"Somewheeeeeere out theeere..."

They don’t make a lot of movies that are set in 18,000 B.C. and told entirely in made-up caveman languages, perhaps for obvious reasons. Nor is the theme of “where dogs came from” often explored in film, though that angle sounds a lot more lucrative. Here to fill those needs is “Alpha,” set 20 millennia ago among the hunter-gatherers of Europe, starring Kodi Smit-McPhee as a teen who becomes separated from his tribe and must find his way home in a harsh but beautiful world, befriending a wolf along the way. The use of a fictitious primitive language (subtitled in English, of course) gives the film an earnest geekiness, which, in addition to the occasionally dodgy CGI, means we’re always teetering on the edge of ridiculousness. But it mostly works, and it’s unusual and ambitious, which is always good for a few bonus points.

Our boy, a soft, willowy lad named Keda, is the son of the tribal chief, Tau (Johannes Haukur Johannesson), and is joining the men for the first time on their annual buffalo hunt. Father and son both take the rite of passage seriously, Tau spending much of the first 30 minutes of the film giving Keda loving guidance and stern correction, emphasizing the principle that everything in life — even life itself — must be earned. When a hunter from another clan observes that Tau must be proud of his son, his reply indicates this has not yet been determined: “I hope he makes me proud.” No pressure, Keda!

As the result of a scary, vertigo-inducing encounter with a herd of buffalo near a cliff, Tau and the hunters come to believe that Keda is dead, or at least beyond saving, and mournfully leave him behind. But Keda is not dead, just badly injured, and here, at the halfway point, is when the film becomes a survivalist adventure, like a PG-13 version of “The Revenant.” Armed with a knife, Keda proves resourceful and well trained, though he still struggles with making fire, and more peril awaits him in the form of flash floods, saber-toothed tigers, and a pack of wolves. One of those wolves, wounded in its altercation with Keda, sticks around and bonds with the kid. The whole premise of the movie — prehistoric boy meets wolf — is thus a spoiler, since it doesn’t begin to happen until the second half.

Written with a sense of innocent wonder by first-timer Daniele Sebastian Wiedenhaupt, the film isn’t long yet could have used some trimming in the first act, leading up to the incident on the cliff. That’s when the story becomes truly engaging, and when director Albert Hughes (on his first solo outing after making “Menace II Society,” “Dead Presidents,” “From Hell,” and “The Book of Eli” with his twin brother Allen) can start showing off the movie’s gorgeous, desolate landscapes. There’s a lot of natural beauty here (it was shot mostly in Canada), and Hughes composes evocative and haunting images. There’s also a lot of CGI, some of which is unconvincing and mildly distracting. But Keda’s journey is frequently thrilling in the way that boys’ adventure novels are, intense but not overwhelming, with a satisfying resolution. I liked it; I think an outdoorsy kid who’s 11 or 12 would love it.

Crooked Marquee

B (1 hr., 38 min.; in a fictional primitive language with English subtitles; PG-13, extreme peril, animal violence, scary situations.)