The Girl with All the Gifts opens disturbingly: children kept in a military prison, cruelly shouted at by adult guards, strapped into wheelchairs and pushed with fearful precision into a grim classroom. It appears to be institutional abuse. But their teacher, Miss Justineau (Gemma Arterton), is kindly. Far more bewildering, Melanie (12-year-old newcomer Sennia Nanua) seems cheerful and eager to learn.

The unsettling mood set by director Colm McCarthy (Peaky Blinders) is only just beginning to unfurl. While much of the sheer brilliance of the film comes in not being able to anticipate where it's going, it's no spoiler to say that this is science fiction horror set in a dystopian near future, ringing bells that resound of everything from 28 Days Later... to Day of the Triffids to Lord of the Flies. But Girl..., adapted by Mike Carey from his own novel, stakes out its own place in a familiar subgenre in ways that are extraordinarily moving and deeply unnerving.

With strikingly fresh imagery and exciting extrapolations of stock SF ideas, it takes you on a journey full of surprises that aren't about cheap plot twists but crafting a vividly told tale in a fully realised alternate world populated by richly conceived, unforgettable characters. Nanua and Arterton are joined by Paddy Considine, bringing subtle depth to a soldier whose relationship with Melanie evolves, and Glenn Close, powerfully challenging as a doctor studying Melanie who is an embodiment of the moral dilemmas at the heart of the tale.

This is a movie to reignite your love of movies if you've despaired of seeing anything different amidst a sea of tired sameness. It is a movie that asks big questions – what does it mean to be human? – and its answers will haunt you. It is a movie that is everything we go to the movies for. Do not miss it.

General release from Fri 23 Sep.