Spoiler considerations severely restrict what can be revealed about Kin.
Like the names of certain cast members, and even the kind of story it tells.
What you can say about Kin is that it pays homage to the sci-fi movies of the 1980s. The Last Starfighter, The Terminator, even E.T. In fact, one way to describe Kin would be to say that it addresses the following proposition: What if E.T. were a gun?
The film opens in Detroit, where an adopted teen Eli (Myles Truitt) lives with his construction worker father (Dennis Quaid), both still grieving over the death of his wife, the child's adoptive mother.
Eli has a tough time in school, is prone to fighting, and likes to spend time alone. After school, he hops on his bike and spends hours scavenging copper and other metals from the city's abandoned industrial buildings.
The grit of post-industrial America is one of the movie's side interests, and part of what makes its hyperspace jump to sci-fi so jolting. Eli is searching an old warehouse when he stumbles upon what appears to be the remnants of a recent alien incursion. Bodies of the dead and near dead litter the floor, futurist equipment is strewn about.
Eli picks up an oblong case, and hides the mysterious object his house, where his ne'er-do-well older brother Jimmy (Jack Reynor) has just arrived, released from prison after serving a five-year term. He's paid his debt to society, but a local gangster Taylor (James Franco) retains a hefty IOU, and in short order Jimmy and Eli are on the road, the criminals in pursuit. Eli takes with him the mystery object, a fortuitous decision, because it turns out be a super-powerful ray-gun blaster, good for dealing with hoodlums. The device is also sought by the beings who brought it to Earth, so they join the chase form Michigan to Nevada.
OK– aliens, gangsters, ray-guns, what's missing? Oh, yeah, pole dancers. Jimmy decides to stop at a strip joint, where a stripper (Zoe Kravitz) makes the impulsive decision to join the brothers on their road trip. Next stop: a casino, naturally. Kin positions itself as a B-movie cobbled together from sci-fi favorites of the past, and so we grant the movie wide latitude to be goofy. It's meant to be out there. Even by those lax standards, though, Kin tries the patience.
Performances run toward the exaggerated — one scene has Franco proving his character's fearsome bona fides by peeing on the floor of a service station. And Reynor's character, meant to have a sort rakish charm that softens his penchant for bad decisions, is consistently off-putting.
The movie has better luck with the casting of young Truitt, who makes an appealing rooting interest, and it is definitely a kick to see Eli, alone, tiny, vulnerable, standing against an array of villains, evening the odds with his awesome weapon.
Carrie Coon turns up as an FBI agent who wants to impound the weapon to learn its secrets, and in the final minutes another actor shows up to explain everything that to this point has not made sense, which is a lot. Sequels would probably explain even more, but none is likely to be forthcoming.