Peter Jackson is no stranger to directing an epic. And with They Shall Not Grow Old, it’s clear that he can take that power to the documentary world as well. Constructed entirely from archival footage from Britain’s Imperial War Museums of British troops in the first World War, the film is masterful, with the director powerfully portraying the scope and terror of the war.

First and foremost, They Shall Not Grow Old is an astounding feat of editing. It’s not necessarily that Jackson and crew found a story within the 100 hours of footage and 600 hours of interviews — material that they didn’t shoot or conduct themselves, but were rather given — it’s that they found a story and evoked its heart and humanity supremely.

It takes a little while to fully invest in They Shall Not Grow Old, as it jumps straight into its method, presenting the archival footage with narration from real soldiers, and no other information to acclimate viewers to the film. But it’s easy to quickly get lost in it as it sinks its hook. It’s a creeping envelopment. 

There are subtle moments — such as the soldiers sitting together, eating and laughing or playing music — that Jackson lingers on. And he and editor Jabez Olssen push in on the faces, meditating on them intimately. The combination of that focus and of the stories the soldiers tell, of minute aspects of their experience such as the grimy water they used for tea or even their makeshift restrooms, makes for a powerfully humanist touch.

There are rather overt cuts that emphasize the humanity within the death. While soldiers tell stories of what happened to someone in combat, Jackson and Olssen cut from close-ups of smiling faces to the sight of someone who’d been killed. It’s very likely that the exact faces and the dead bodies aren’t the same people, but that’s beside the point. What They Shall Not Grow Old gets at is that any young man could be killed and killed gruesomely, and that they all, at one point, smiled. It makes for a particularly harrowing sequence.

And Jackson and crew should also be commended for their humanist nuance. Averse to politics, the film highlights the relationships that British troops occasionally developed with the German soldiers whom they captured. Many Germans didn’t want to fight, just like many British, and they could find common ground. And in traveling back home after the war, the film also emphasizes the isolation the soldiers felt, making for a narratively wholesome portrait.

It’s tough to see any of this landing as well as it does, however, were the film not an absolute technical marvel in regard to its sound, its colorization and even its utilization of 3D.

It’s easy to forget that the sound is not actually native to the footage — a testament to the depth of the work. Seemingly every little piece of visual information that would result in sound is accounted for, from distant chattering to walking through mud. And not only is the foley work fantastic, but the mix, particularly during combat sequences, evokes an atmosphere that feels native.

The colorization is immensely impactful too. It doesn’t happen until the soldiers are truly in the trenches, but when that moment comes, it’s quite staggering. It’s almost impressionist painting-like with how the grain is filled in and swims with greater vibrancy and depth. But it also opens up the reality of the world of the war in ways that only color can. Just like the minutiae of the soldier’s experience elevates the film, the minutiae of the colors — the mud, the uniforms, the grass — enhances one’s ability to inhabit that world. 

That’s also where 3D comes in. They Shall Not Grow Old quite literally becomes a window to another world as, at the beginning and end of the film, the image is framed as a small window within blackness on the screen — with the 3D realizing the world on the other side. It’s a very a simple choice, but it’s profoundly effective, as one can feel the presence of the world beyond the frame. When all three of these elements are working at full force, the film offers unparalleled immersion.