Otherworldly science fiction meets down-to-earth psychological realism in director and co-writer Michael Pearce’s impressive follow-up to 2017’s brilliant Beast. Boasting yet another standout performance by Riz Ahmed, the nuances of which are superbly amplified by Jed Kurzel’s slowly mutating score, this is a genre-hopping affair, balanced between tangible personal experience and growing paranoia, an affecting meld of inner and outer worlds in which family stresses and extraterrestrial spectres collide. Like Nic Roeg’s The Man Who Fell to Earth, to which this owes a tonal debt, Encounter opens with images of objects plummeting through the atmosphere toward our planet’s surface. From here we move to Blue Velvet-style closeups of insects, vividly illustrating alien microbes entering the ecosystem. Then we’re in Apocalypse Now territory, as Ahmed’s Malik Khan awakens in his hotel room. “This violence is endemic,” proclaims TV news coverage of a plague of rioting. “It’s like a disease that’s infecting a growing area.” A decorated marine, Malik is now deep in a secret-ops battle against microscopic space invaders – and it’s clearly getting under his skin. He hears bugs in the wall and obsessively covers himself in insect spray. One night he sneaks into his estranged wife’s home and gathers up his young sons, Jay and Bobby, telling them that they are going on a surprise road trip. “Why do you have pictures of monsters?” one child asks after rifling through his luggage. “They’re not monsters,” Malik replies. “They’re non-terrestrial micro-organisms”, invaders that live inside their hosts, controlling their actions. Apparently, the boys’ mum has already succumbed to these space spores, as has a cop who flags Malik down in the middle of the night, and in whose eyes he sees tell-tale signs of infection. There’s a strong strain of William Friedkin’s criminally underrated 2006 chiller Bug (from Tracy Letts’s stage play) in Pearce’s evocation of a scratchy threat that drives our protagonist to distraction. From the increasingly frenzied tempo of the bug-zapper on his sons’ porch to a closeup of their mother falling prey to a mosquito (“I’m getting eaten alive today”) and then mysteriously getting sick, it’s the little details that bite. As with any family road-trip movie, there is humour too. “It’s official – you’re both infected,” jokes Malik when his sons tell him to turn off the heavy metal blaring from his car radio, preferring the sounds of K-pop and Barbra Streisand. Meanwhile, in a parallel narrative, Octavia Spencer keeps things grounded as parole officer Hattie Hayes, a proud “benefit of the doubt” type who finds herself locked in a nightmarish world of “family annihilators” and suspected kidnappings when suited government agents come calling. At first, Encounter seems to be following in the footsteps of such M Night Shyamalan thrillers as Signs or The Happening – films in which an apocalypse starts quietly, before growing into a global cataclysm. But Pearce and Giri/Haji creator Joe Barton (who wrote the original speculative script) are more interested in interior narratives, subtly linking Malik’s current struggles with the PTSD-inducing scars of former battles. Having tried to protect his kids from their more dreadful purpose by selling this “rescue mission” as a game, Malik finds fairytales turning to reality. “You’re not a kid any more,” he tells Jay, “you can’t be”, suggesting that dire circumstances have already robbed his son of his childhood. Or perhaps it’s a growing awareness of their father’s fallibility that is the kids’ real wake-up call. The camaraderie of the Three Musketeers is invoked as the trio declare that “families take care of each other”, even as the cracks in Dad’s warrior armour are laid bare. Terrifically engaging and naturalistic performances from young actors Lucian-River Chauhan and Aditya Geddada add emotional weight, making this a family affair. Meanwhile, Beast cinematographer Benjamin Kračun, whom Pearce directed towards Invasion of the Body Snatchers and Paris, Texas as reference points, carefully delineates the film’s shifting perspectives, slipping between subjective and objective views, emphasising the alien elements of the story without ever losing sight of its core humanity. In cinemas now and on Amazon Prime Video from 10 December