From left, Riz Ahmed, Lucian-River Chauhan, and Aditya Geddada in Encounter (Amazon Studios)

Genre films, particularly sci-fi and horror, generally use certain tropes as a gloss, to focus on something else, whether it is the connection between sex and death (all slasher films), sacrifice (The Exorcist), or giving and receiving life and love even if you know how it will end (Arrival). Some films trick you into thinking they are one type of movie and flip into a different kind of story or, in the best of the “that’s-not-the-genre-you-think-it-is” genre, slowly reveal what the movie is really about. Encounter is one example. It begins with an alien invasion and turns into something else, but it still doesn’t discount that you may still be watching what you think you’re watching.

Malik (Riz Ahmed) is on a secret mission and has been away from his family for two years. His sons Jay (Lucian-River Chauhan) and Bobby (Aditya Geddada) have been missing him desperately. In the dead of the night, Malik steals the boy away from his estranged wife’s home in Oregon. He reassures them he’s heading to a scientific base in Nevada and also reveals his mission: fighting non-terrestrial microscopic organisms that take over and control humans. The boys believe him unequivocally that he will protect them, and because the film has so far been told from Malik’s perspective, so does the audience.

And it’s a chilling perspective. The film begins with a meteor hitting Earth, followed by ominous, extreme close-ups of feasting insects, including a praying mantis chowing down on an unfortunate victim and a microscopic parasite entering the bloodstream of a human. Throughout the movie, roaches skitter out from behind paintings and air conditioning vents. Then there’s Malik, wide eyed and tense, waking up from a dream, or perhaps a nightmare, and immediately spraying bug repellant all over his body. He has done 10 tours with the Marines and, like most of Ahmed’s characters, he’s barely holding his nerves together. That said, he immediately bonds again with the boys, who adore and idolize him, even when he barrels down the highway in a stolen pickup truck driving at a hundred miles an hour.

Director and co-writer Michael Pearce has successfully crafted an ominous sense of menace, until cracks begin to appear and suddenly we are not sure to believe Malik. Pearce allows this sense of doubt to grow along with Jay, the elder of the two kids, who is a sensitive 10-year-old with a talent for drawing. To say more of what will happen will spoil the surprises ahead, which, for the most part, Pearce navigates effectively. The denouement is pat, but even then, the film does not end as many of this ilk do.

What really allows the movie to succeed is Ahmed and the performances Pearce coaxes out of the children, who act like actual kids. There is no preciousness or precociousness one can find in filmic portrayals of children. Jay and Bobby feel authentic, and the relationship between them and their father is the heart of the film. Ahmed, quickly becoming one of the great actors of his generation, projects a stern but loving exterior while the audience sees signs of the coiled, anxious, and damaged man underneath. The only time Malik seems in complete control is when he finds himself in a combat situation.

As I said, genre films are generally about something other than what they seem to be about. Encounter is about family and how far one will go to protect loved ones, and, in that sense, Encounter succeeds.