Plot summary of Xenoblade Chronicles 3

This page describes a plot summary of Xenoblade Chronicles 3. It is not a full description nor a complete novelization, but simply an overview of major events.

Chapter 1: Ouroboros
A group of four kids dashes through a dense crowd awaiting the Queen's Anniversary. The clock strikes six, and time stops for all but one of the children. He looks up to see a planet in the sky, its shadow casting over the land.

In a starry abyss, two masses of energy meet. Across an unknown landscape, spherical chunks of terrain vanish in flashes of light. A battlefield comes into view, with footsoldiers and giant machines on both sides. Keves is the side wearing black and blue, while Agnus is in white and yellow. The battle is eventually won by Keves, and the Agnus machines are depleted and fall.

In this world, Aionios, killing the enemy faction empowers one's own with their life force. People are "born" as child soldiers, said to be from the Queen of the country, and know nothing but fight. They only live up to ten years (called "terms"), and those who survive that long are honoured in a Homecoming by the Queen as they fade away. The narrator, Noah, is an "off-seer", one who plays a flute melody to honour the dead (by battle or by Homecoming). He grew up in a friend group of himself, Lanz, Eunie, and Joran; today, he fights in a unit with Lanz, Eunie, Riku, and Mwamba. Since Noah likes to see off the enemy if their off-seer is dead, they tend to get left behind, and they must make the trek on foot back home yet again.

On arriving back to, the gang hits the showers. It's implied that Joran was killed shortly after a disagreement in the group's youth, and it's part of why Noah became an off-seer. The next day, a royal decree arrives and is visualised through the soldiers' Irises (essentially a modern-day smartphone and VR overlay in humans' eyes): a large mystery transport needs to be intercepted, and its ether cargo destroyed. The army deploys and advances through the Yzana Plains and into Alfeto Valley, killing the creatures that block their way and gaining minimal amounts of charge for the Flame Clocks in their eyes (much like those that power the colonies' giant machines). Mwamba talks about how his Homecoming is in a month, so he wants to transfer out of active service, and leaves the group to go on ahead.

The Keves army reaches the target first and begin to fire on a cloaked ship, with Agnus troops not far behind. The mystery ship loses cloak and makes a hard landing, deploying unmanned ground forces to protect itself as both sides approach while fighting each other, and the grey-wearing crew digs in to protect a glowing egg-shaped "Ouroboros Stone". The defenders are whittled down to just Guernica as the party approaches, who end up in a fight with three elite Agnus troops, including their own off-seer. The battle dies down and Noah becomes suspicious, so he stops fighting to kill and starts trying to talk, though he gets nowhere until Guernica interrupts the fight himself. He tries to tell the two groups who their "real enemy" is, but gets stabbed by a projectile from a new arrival: a giant humanoid monster with Mwamba in one hand and an Agnian, Hackt, in the other. The monster, which Guernica calls a Moebius, goads the soldiers to try and fight each other again by killing his captives. Guernica manages to get into the downed ship and fight the Moebius for a bit, but the ship is torn apart. All this only spurs the two groups of three soldiers into fighting the Moebius together. Guernica takes advantage of the distraction to open and activate the Ouroboros Stone, which causes Noah and the Agnian off-seer Mio to have an out-of-body experience and fuse together into a single larger form. The Moebius says they've used an Interlink to merge into an Ouroboros, which makes them his mortal enemies. After further fighting, the Moebius concedes defeat and leave, but not before projecting an infinity symbol into the sky, visible to many across the world. Noah and Mio return to normal and an uneasy truce forms. Guernica explains that all six of them are now Ouroboros, that he is sixty years old, that they must fight the Moebius coming after them, and that they must go to his City in Swordmarch to reclaim the proper way of things. He finally dies, and the two off-seers send him off. Noah and Mio use the fact that they shared memories to reduce the tensions between Lanz and Eunie, and Sena and Taion. They then make to return home.