You need to watch the best post-apocalypse thriller on HBO Max ASAP

Two extraordinary pieces of zombie fiction debuted in 2013: video game developer Naughty Dog’s acclaimed The Last of Us (which earned a sequel and upcoming HBO adaptation) and M.R. Carey’s Edgar-nominated short story “Iphigenia In Aulis” (shortly thereafter expanded into a novel titled The Girl with the Most Gifts).

In both, fungal infections turn most of the world into raving monsters, though a young girl in the midst of this apocalypse could hold the cure to saving humanity. Carey’s story – adapted into a fascinating 2016 thriller (now streaming on HBO Max) – differs from The Last of Us in one crucial, thrilling way: that young girl is a zombie herself. (Kind of.)

The movie in question, titled The Girl with All the Gifts, first found life as a short story written over a four-day period, with Carey calling it “one of those rare situations where the story obsesses you so much that you use every spare moment to write some more of it down.” The author started with a single image: that of a young girl named Melanie “sitting in a classroom, writing an essay about what she was going to do when she grew up. Only the girl is already one of the undead and doesn’t know it.”

Carey had collaborated director Colm McCarthy on another adaptation that fell through, but their bond was strong enough for Carey to pitch him on a film driven by that same image. Very quickly, the author had a short story, a novel, and a movie all in the works simultaneously.

As played by Sennia Nanua, who was BAFTA-nominated for her work, The Girl with All the Gifts’ Melanie is certainly a fascinating protagonist. The story’ post-apocalyptic world is quite brutal on humans, who are plagued by a legion of zombies known as “hungries.” But it’s even worse on Melanie and other children, who aren’t quite children at all. Appearing normal until they get a whiff of human flesh, these hybrid zombie-human children are capable of going sicko mode on any human around and so spend their days locked up in an underground military base.

It’s in this grim place that The Girl with All the Gifts establishes Melanie’s daily routines and her three guardians. She attends classes taught by the kind Helen Justineau (Gemma Arterton), meant to keep the children busy, and submits to tests by the cold Dr. Caldwell (Glenn Close), aimed at finding a cure. Looking out over all of them is harsh military leader Sgt. Eddie Parks (Paddy Considine).

All these actors are typically a delight to watch on their own but in this film showcase strong chemistry with one another. After their military base collapses to hungries, the three adults and their undead pupil are forced to work as a team, along with two junior soldiers. And as they do, their appointed roles begin to shift, with Dr. Caldwell becoming kinder to Melanie, Justineau confiding in her fellow adults the weight of bearing Melanie’s affections, and Melanie starting to discover her roots.

At one point, Melanie is suddenly surrounded by hungries, all of whom ignore her scent in their frenzied hunt for human flesh. But just because they ignore her, that doesn’t mean she’s in the clear. Chased through London, the group tiptoes through massive crowds of the undead.

Known for directing high-end TV series like Black Mirror and Sherlock, McCarthy brings a sense of versatility to his camera. As the group infiltrates a crowd of hungries, he creates a sufffocating aura of mud-caked closeness. Also flawlessly executed is a tense scene in a maternity ward, where Caldwell explains to Melanie the odd nature of her birth and Justineau observes the actions of a particularly forlorn hungry.

But the movie’s strength lies in Melanie’s realization that being part-zombie is not actually such a bad thing. Like the other children, Melanie is a second-generation hybrid, created through fungal mutation and existing between two worlds. In the beginning of the film, Melanie’s true nature is treated like a sin, and those like her are locked away or constantly shackled. Parks calls the children abortions, which Melanie later turns into a common slur, referring to everything she doesn’t like as “a friggin’ abortion.” But equally worrying is how Dr. Caldwell views Melanie, with the cold calculation of a scientist looking purely at a mutation, not sensing the person in view as well.

As the team progresses through a dangerous landscape, they find themselves relying on Melanie. The movie’s axis slowly starts to shift, with The Girl with All the Gifts asking surprisingly intense questions of its characters and world. What is the purpose of human knowledge? What does societal change feel like for those ways of life are ending, and for those whose day is dawning? And, of course: what would a roving gang of child half-zombies taking over London even look like?

The Girl with All the Gifts provides answers for all of these questions, resulting in a fascinating last scene. Suddenly, the world as we knew it is gone, and a new one must be created. But who’ll be left to pick up the pieces and start life over again?

The Girl with All the Gifts is now streaming on HBO Max.