Most of the press around 1917, Sam Mendes’s Oscar-nominated World War I epic, has focused on the film’s technical virtuosity. The movie’s timeline unfolds over the course of a day—from one afternoon into the following morning—and that’s shown through two extremely long, unbroken tracking shots.

For some directors, the long take is simply a flashy move, something that serves no purpose other than to allow the filmmaker to show off. But when done well, it immerses the audience in the scene. If the action is literally unfolding all around the camera, it’s easy to convince viewers that they, too, are in the thick of it. It’s a gimmick, to be sure, but Mendes and cinematographer Roger Deakins make it work for 1917. This film is always in motion, even when it’s stopping to catch its breath, and the race against the clock seems all the more urgent because we see each second tick off.

As impressive and adroit as the long-take structure may be, though, it’s not the best part of 1917. This film has a hundred explosions and a thousand background players, but only about one and a half characters. And it makes its main character, Lance Corporal Will Schofield, count.

Schofield, as portrayed by English actor George MacKay, is a one-man canvas onto which the horrors of war are painted. He’s allowed to be nuanced and complex in ways most protagonists of war films never get to be. In the space of half a day, Schofield experiences the extremes of human experience, filtered through the particular charnel house of the western front of World War I. MacKay wears those experiences on his face, running the gamut from fear to resolve to total despair and exhaustion, all while keeping his character’s cartoonishly hellish existence relatable to modern audiences.

World War I was uniquely horrific for a number of reasons, and those reasons also explain why it’s so difficult to make a World War I film feel kinetic. The Great War took place at a time when humanity had developed a set of truly devastating and inhumane weapons, ranging from machine guns to poison gas to artillery pieces so powerful their crews had to account for the curvature of the earth while aiming. But while those devices existed, the means to counteract them had either not been developed or appeared only in the waning months of the war.

Those weapons changed the nature of war, and wrought unprecedented horrors on those unfortunate souls tasked with fighting. World War I began with a month-long German advance through Belgium and France, which was stopped in early September at the First Battle of the Marne. After that, the two sides dug in and reinforced their positions, leading to a stalemate that lasted for about four years. Soldiers lived and died, ate and defecated in glorified holes in the ground. Merely sticking one’s head up above the lip of the trench could mean instant death by sniper or machine gun fire. Leaving one’s trench to attack the enemy involved running through a hail of bullets and a thicket of barbed wire.

Such human wave attacks routinely resulted in tens of thousands of casualties for negligible gains, leaving the opposing sides to fight repeatedly over the same patch of ground that was being transformed into a toxic moonscape in the process. The Belgian town of Ypres saw four major battles that totaled as many as a million casualties put together; none of those battles moved the front line more than a few miles. Meanwhile, the Italian and Austro-Hungarian armies fought no fewer than 12 battles over the same patch of the Isonzo River Valley in 29 months.

Never before or since in human history have so many lives been spent with so little to show for it. Even soldiers at the time began to realize the futility of their efforts. From the famous Christmas Truce of 1914 to the French army mutinies of 1917, men on both sides saw that their lives were being wasted to kill people with whom most rank-and-file infantrymen had no quarrel whatsoever. In contrast to most wars throughout history, World War I didn’t knock out armies; it knocked out entire nations. And it ended only when the German Empire’s political and economic base collapsed under the strain of the fight.

Hollywood, for all its alleged liberalism, is ill-suited and usually disinclined to tell a war story of pointless slaughter. From Audie Murphy to Top Gun, the movies and the military both benefit from the myth of war being both righteous and morally clear. Vietnam made it acceptable for polite Americans to find endless military struggle unsettling, but not necessarily to question the myth of Allied invincibility and righteousness.

Nevertheless, as filmmakers shaped by World War II handed off the baton to filmmakers shaped by Korea, Vietnam, and the war on terror, the costs of war became a point of contention. Even if war is necessary, must the tree of liberty be watered by the blood of so many patriots?

So Tom Hanks’s Captain Miller of Saving Private Ryan is still an everyman schoolteacher from Pennsylvania who gladly takes up arms to protect Uncle Sam from the Nazis, but his compass hand shakes sometimes and he turns pale when he accidentally dumps a bucket of viscera over his head on Omaha Beach. Courage Under Fire is a film about an officer suffering from debilitating PTSD while investigating a Pentagon cover-up, but nobody questions the righteousness of the cause (the first Gulf War) for a moment. Even films that are more openly skeptical about the value of war for war’s sake, like Full Metal Jacket or Apocalypse Now, show soldiers broken by fighting as callous dropouts or delusional murderers, not as complex men who suffer complex effects from fighting.

Here, Schofield is a welcome exception. Despite his youth, he serves as a sort of mentor to the babyfaced Lance Corporal Blake, who is set up to be the film’s protagonist before he’s stabbed in the gut by a downed German aviator. Schofield has won a medal for valor, but values it so little that he traded it to a Frenchman for a bottle of wine. Nevertheless, he impresses on Blake—who’s still earnest enough to find the idea of war heroism seductive—that his actions are enough to earn a medal of his own. (A posthumous one, it turns out.) Schofield tearfully expresses how painful it is to go home on leave, knowing he’ll have to return to the front, but does not reveal until the very end of the film that he has a wife and young children waiting for him back home.

Schofield is not merely some shell-shocked object of pity, or a cold-blooded killer, or an Audie Murphy type who’s ready to sacrifice all for king and country. At different points in the film—sometimes in a span of just a few minutes—he’s all three. Late in the film, we see Schofield lavish his entire stash of hoarded rations, a collection he’d hidden even from Blake, on a French woman who’s caring for an abandoned infant in the bombed-out ruins of Écoust. Moments later, he’s strangling a German soldier to death with his bare hands. (The soldier, according to the credits, is named Baumer, no doubt an homage to All Quiet on the Western Front, still the definitive literary text about the complex effects that trench warfare had on the people involved.) From there, he escapes further German resistance by leaping into a river and going over a waterfall, where he washes up at his intended destination looking like the very definition of the thousand-yard stare.

Then he comes to his senses and runs like hell to finish his mission.

It’s refreshing to see a war movie that packs so much complexity into a character in so little time and exposition. 1917 has nothing to say about whether the Allied cause was just, only that it was horrifying. Schofield is asked to crawl over corpses, inadvertently sticking a hand with an open wound inside a dead soldier’s body, and that’s not one of the five most traumatic events of his day. More than that, he commits incomprehensible acts of violence himself; 1917 features some classic war movie shooting deaths but also brutal hand-to-hand fighting that would undoubtedly leave the survivor traumatized for life.

And because we spend two hours looking over Schofield’s shoulder, we’re thrust inside his head, to think about how—in the unlikely event he survives the eight months left in the titular year—Schofield is supposed to go back to his wife and kids and just carry on like normal. That’s a much more powerful and thoughtful depiction than most cinematic soldiers get, and it ought to be the most enduring part of the film’s legacy.