"The Last of Us Part II" is an astonishing achievement - a searing demonstration of how a video game can marry heart-stopping gameplay, gorgeous environmental storytelling and anxiety-inducing moral complexity.

Though it uses the tropes of the zombie apocalypse, it completely transcends the genre. "The Last of Us Part II" is not a game about zombies. It's a meditation on loss - not simply loss of life, but of community, family, and individual capabilities - and the effort it takes to muddle through maddening grief.

"The Last of Us" (2013) told the story of Joel and Ellie. Joel is a middle-aged smuggler hired to transport Ellie, a young teenager, across the country. They head out West to meet up with the Fireflies, a hard-pressed group of survivors living in the shadow of a collapsed society who hope to use Ellie to synthesize a vaccine to counter the plague that has turned most of the human population into flesh-chomping monstrosities.

As it stands, Ellie is the only known person to have survived being bitten by "the infected." From the beginning Joel tries to remain unattached to her to ward himself from potential suffering. But eventually he comes to love Ellie as a daughter. After delivering her to the Fireflies, he is emotionally undone to discover that she will have to forfeit her life for the manufacture of a vaccine. Though Ellie is fully prepared to sacrifice herself for the good of humanity, Joel ignores her wishes and forcibly removes her from the medical facility while she is under anesthesia, then lies to her about the incident.

The episode at the hospital is repeatedly revisited and examined from different angles in "The Last of Us Part II," which picks up a few years later with Joel and Ellie living among a small community of people in Wyoming. In the intervening time, a rift has opened up between them as Ellie has come to be more self-reliant.

Due to the incredibly restrictive nature of the embargo agreement, there is much about the plot, the characters, and the overall structure of "The Last of Us Part II" that I can't discuss. What I can say is that after weathering a harrowing loss, Ellie travels out to Seattle to settle a vendetta. Her journey is one of the bloodiest treks in video game history. (I can't think of another game that makes, say, the amputation of a limb a longed-for best-case scenario.) Although many packs of zombies lie between Ellie and her goal, it's the violence orchestrated by humans against other humans that lingers in the mind.

When Ellie kills someone, they rarely go meekly into the gentle night. Unless she performs a "silent takedown," i.e. sneaking up on someone and slitting their throat, her victims will often spend their remaining seconds pleading for their lives, wailing, or calling to their loved ones. The developers go to tremendous lengths to humanize many of Ellie's adversaries. Indeed, the towering achievement of "The Last of Us Part II" is that it's constructed in such a way that by the end I wanted nothing more than for Ellie to renounce killing because of the psychological harm it was inflicting on her and those around her.

How gloriously paradoxical is it that one of the finest action games ever made pushes things to such an extreme that I wanted to reject its central game mechanics? At certain points during the second half of the story I found myself reluctant to press the buttons that would lead to injury of another character. Talk about a mind trip.

What makes this level of violence bearable are the sections of downtime generously spread throughout the campaign. Watching Ellie and Joel stroll through a museum, for example, is as interesting as any of the action sequences. So expressive are their words and their looks. The developers at Naugthy Dog have a flair for narrative pacing. Characters are treated to moments of aesthetic exultation - times when they lose themselves in the beauty of a scene or the company of another. This technique makes them that much more endearing, that much more soulful.

As I moved from one extraordinarily rendered environment to the next - simply coming across a light source in a room can be diverting - the staggering amount of detail on display everywhere made me mull over the human cost that goes into making something on the scale of "The Last of Us Part II." In an industry notorious for asking employees to keep long hours, the perfectionist culture at Naughty Dog still stands out.

An article in Kotaku by Jason Schreier describes the onerous labor conditions around the project. In it, he quotes a developer for "The Last of Us Part II": "This can't be something that's continuing over and over for each game, because it is unsustainable," the developer said. "At a certain point you realize, 'I can't keep doing this. I'm getting older. I can't stay and work all night.' " (Notably, Schreier reported on the perfectionist culture at Rockstar Games, whose "Red Dead Redemption 2" is one of the only games that can compete with "The Last of Us Part II" on a visual level.) It's for that reason that I could not help but read into this letter which Ellie finds in her travels:

"Eugene -

"I'm begging you to come home!

"The Fireflies want to save the world - I say let them. ... Let them develop a vaccine to save mankind. Maybe one day we'll live to see the fruits of their fantasies. Until then, I have to put our daughter first.

"The Fireflies will be fine without you. Your daughter won't."

"The Last of Us Part II" is one of the best video games I've ever played; I hope the cost to the developers was worth it.

"The Last of Us Part II"
Developed by: Naughty Dog
Published by: Sony Interactive Entertainment
Available on: PlayStation 4