Bagger finds Reis sitting alone in the dugout, a marked departure from his usual imperious posture. Reis greets him with slow contempt and delivers a bitter monologue about ingratitude toward men of vision, then lectures on what he labels the European Disease: a supposed pandemic of cowardice and tactical indecision that disadvantages the Allied troops. On the map table, Bagger notices elaborate wooden-block formations representing a grand plan Pershing clearly rejected. Reis confirms his replacement is coming, framing it as another injustice.

Sensing his window is closing, Bagger blurts that the screaming figure from Bois de Fays was not human. Reis orders him not to uncover the body and threatens to place him in a psychiatric hospital and give him a dishonorable discharge. Bagger ignores the threats and pulls back the angel’s hood. The dugout fills with her light, and Reis’s fury dissolves.

The angel’s radiance illuminates the dugout, revealing its cramped comforts: a real bed, wine, books, and an untouched dinner Pershing had refused. A hand-carved cuckoo clock ticks in the otherwise silent room as Reis stares. He asks what she is; Bagger answers: an angel. Reis touches his chest medals, fingers pausing over the empty space reserved for a Medal of Honor, and whispers the name “Minerva.” Bagger, ignorant of the reference, goes along with it.

Bagger lays the angel on the map table and recounts how she saved him and Arno from a mortar, raised the dead to stop Veck, and resurrected Arno. The word “resurrection” lands hardest. Reis sharpens, declaring that if she can do the impossible, the impossible is what he will demand. He tears open his uniform to expose his underdeveloped right arm and, weeping, begs Minerva to restore it. Bagger nods his assent. The angel closes her eyes, her light pulses, and Reis’s arm is grotesquely disassembled and rebuilt tissue by tissue.

Reis raises his new arm, flexes his fingers, and makes a fist for the first time in his life. His disbelief melts into gleeful laughter that unnerves Bagger. Reis lifts the angel, declares her the ultimate wonder weapon, and names her his Minerva. Bagger protests she is a healer who could end the war outright, but Reis talks over him. His plan: sabotage the approaching Allied victory, allow Germany to reverse the tide into years more of slaughter, then deploy Minerva to win single-handedly and claim the Medal of Honor. Bagger realizes that Minerva, the goddess of war, is the figure on the medal Reis obsesses over, and that the angel has become the literal object of his ambition.

Reis waltzes with the angel using his new arm, then kisses her hard; they collide and her fingernail nicks his palm. He sucks the blood and calls her “the Adversary,” a name that strikes Bagger as more truthful than any other. Reis dismisses Bagger curtly. Bagger salutes and climbs out, feeling hollowed.

At dawn, Bagger wakes to a surprise German artillery barrage. Motivated by the need to keep the angel from capture, he joins the rush to the front. Someone tosses him a Browning Automatic Rifle (BAR) and genuine bloodlust rises in him for the first time; fellow soldiers welcome him, and for a brief moment he belongs. Just as Bagger plants himself at a firing position, Arno, who followed in spite of Bagger’s dismissal, yanks him off the ladder and hurls the BAR away, shouting that Bagger promised the angel he would never kill.

After a flash of rage, Bagger weeps and the two embrace in the trench water. Arno insists they must save the angel and tells Bagger something that lands as immediate truth: The angel never belonged to their group of five soldiers. Either she belongs to Bagger, or Bagger has always belonged to her. A second realization strikes Bagger: his Rochambeau victories against his former companions mirrored the eventual causes of their deaths. Goodspeed was cut down by shrapnel (scissors), Popkin was crushed beneath a wall (rock), and Veck was killed after encountering a written note (paper). The angel interpreted Bagger’s winning symbols as directives; Bagger has been their killer all along.

Arno guides Bagger back through the battle to Reis’s dugout. Bagger worries incessantly: He also beat Arno in Rochambeau but cannot recall which symbol, and without knowing the method of the boy’s foretold death, he cannot prevent it. They reach the heavily damaged dugout, descend past burning debris, and find the interior wrecked and empty. Panicking, Bagger tears apart what remains and smashes the cuckoo clock before Arno spots a wooden trunk. Bagger presses his ear to it and hears the angel pleading to be saved. They break the lock together and free her.

The reunion is cut short. Reis emerges and attacks Bagger with his gold-tipped walking stick, shattering fingers, tearing open his cheek, knocking out teeth, and destroying his left eye. Reis then turns on Arno, beating the boy while wrenching at the angel. Bagger finds Reis’s dropped Colt .45 on the floor. He levels it at the back of Reis’s skull but finds it difficult to act because of his vow. He screams to the angel for help. In response, a chorus of animal calls from across the world builds and converges into a single shriek.

Time freezes, bringing the chaos of the surrounding battle and the brawl in the dugout to a halt. The angel stands free behind Bagger, her bearing utterly transformed: composed, sharp, and powerful, every trace of prior meekness revealed as performance. She extends her hand; Bagger places his broken one in it. They ascend above the battlefield frozen into a vast, static scene of death, pass a frozen German triplane, and continue climbing into bitter cold until Bagger perceives an enormous, soft fold in the sky above. The angel carries him inside.

Bagger finds himself inside a perfect recreation of his father’s church. On the altar lies his red leather Bible; opening it, he finds a reproduction of the Raphael painting, the Solly Madonna, and recognizes the angel’s face in the image of the Virgin Mary. The angel has been a presence in Bagger’s life since childhood. Turning more pages, he discovers three bullet holes drilled through the back cover: the Bible stopped rounds that would have killed him fleeing across No Man’s Land. Bagger interprets this to mean that his father, who pressed the Bible into his hands at their final meeting, saved his life. Bagger weeps.

The angel asks what Bagger wants. Bagger answers that he only wanted to protect her the way his father protected him. He turns to find her enormous, holding a massive sword, the church walls dissolved into jungle. She dismisses the Angel of Mons as myth and states that God sides with no nation. Bagger demands she destroy humanity if war is inevitable; she asks how his father described the end. He answers automatically: a divine plague. He connects this to the spreading Spanish flu and wonders whether the angel’s original mission was to deliver that plague to end humankind, a mission he may have only delayed by rescuing her. He asks her to explain the reason behind her mission. She tells him she has been absent 60 thousand years and now has permission to show him the answer, warning that the revelation will haunt him forever, though she predicts that he will ask anyway. He does.

The angel carries Bagger to the Earth’s core, which houses a colossal infernal engine that processes the bodies of every person ever killed in war, reducing flesh to tar and forging it into bullets. Grief is the fuel, vengeance the output, and the cycle has been civilization’s engine from the beginning. Bagger witnesses a procession of future wars fought using new weapons, by new nations, producing tens of millions dead, each conflict feeding the same machine. Lifting above it all, he sees the Earth itself as a wounded giant, not immortal.

The vision implies the only way to break the cycle is deliberate self-sacrifice, inspiring others toward nonviolence, as his parents did. Bagger also understands that the angel’s prohibition against killing was not a condition imposed on him, but a description of what already exists. The angel returns him to the dugout.

Time resumes. Reis is mid-swing, seconds from killing a severely beaten Arno, who still grips the angel. Bagger weighs his options: Either he kill Reis and break his vow, or hold back and let the boy die. He chooses Arno and shoots Reis in the back of the head. As the dugout roof collapses, Bagger throws himself over Arno and the angel; the cave-in partially buries his legs, but they quickly dig free. The angel beckons to Arno, who takes her hand and follows her toward the ruined stairs, which Bagger believes will lead Arno to the death his Rochambeau victory foretold.

Unable to pursue with his broken hand, Bagger picks up the pistol and holds it to his own temple. He shouts to the angel that his vow only forbade taking others’ lives, not his own, and offers himself to balance the scales for killing Reis. Arno, registering what is happening, abandons the angel’s hand and sprints back to stop him. Bagger smiles at the boy with genuine love and pulls the trigger.

The gun fires but causes no new pain. Bagger’s remaining eye finds the bullet suspended an inch from his face; the angel has stopped it again. She plucks it from the air, holds it with careful tenderness, meets Bagger’s eye, touches his ruined cheek warmly, remarks that he is always full of surprises, and turns away. He understands the warmth is gone for good.

The angel walks out into the battle. Bagger and Arno chase her into No Man’s Land, surviving the crossfire through sheer momentum, until they find her kneeling in a shell crater. She buries the bullet in the clay with a gardener’s deliberate care. Watching, Bagger experiences a rushing vision: the Argonne forest regrows over decades, and a massive tree rises from the buried bullet. An elderly Bagger, who wears an eye patch and has been brought to the site by his future family, kneels at the trunk of the tree, lays a hand on the bark, and whispers that the angel was right about everything. However, the elderly Bagger regrets nothing. Bagger laughs, and the shamefly exits through the wound in his cheek and flies away.

The vision ends. The angel convulses, her skin hardening to scales, her spine splitting, enormous leathery wings unfolding, obsidian horns replacing her halo. The transformed being ascends into the sky and vanishes. Bagger stands in the crater holding Arno’s hand and a second, unseen hand, its grip calloused and arthritic, unmistakably reminiscent of his father. He waits to see if enough life remains in him to climb out and begin again. The novel ends with a long, looping series of “and”s that circles back to its opening line, in which Cyril Bagger considers himself lucky.