Plot summary of Xenoblade Chronicles X

Prior to the Prologue
In the 2020s, a xenoform makes contact with the governments of Earth. The xenoform warns them of a coming war which will devastate the planet. In response, the Earthlife Colonization Project, a plan to move humanity onto other habitable planets, begins. In particular, Project Exodus, a plan to evacuate the population of Earth on giant spaceships called Arks, is initialised. Contact with the xenoform also leads to technology advancing at a rapid pace, leading to inventions such as Skells, giant bipedal vehicles which are very useful for battle.

Prologue: Awakening
In July of the year 2054, two alien alliances, the Ghosts and the Samaar Federation engage in battle over the skies of the Earth. The collateral damage of this battle leads to the planet being completely devastated. Fortunately, the United Federation sends a group of spaceships known as Arks into space in order to preserve the human race. Unfortunately, most of the Arks are also obliterated attempting to escape the earth due to being hit by alien weaponry.

The White Whale, containing the city of New Los Angeles and a population of 20 million people, is one of the fortunate few to escape Earth's cataclysm. It spends two years in space, searching for a planet to land on. However, the ship is pursued by a faction of the Samaar Federation known as the Ganglion. Through the concerted efforts of the soldiers and skells on the ship, especially the Ares piloted by Elma and her superior, the Ganglion are repelled. However, the ship still sustains a high degree of damage causing it to crash onto a nearby habitable planet. Furthermore, Elma's superior is lost in the chaos.

The White Whale is destroyed upon entry to the nearby planet, causing its shrapnel to be scattered across the planet. The habitation unit containing the city of New Los Angeles, however, survives intact due to its barrier activating and the use of an impact gel which crystallizes upon collision. The remaining residents of New Los Angeles establish a new civilian government, headed by Director-General Maurice Chausson and a military force, B.L.A.D.E headed by defence secretary Kentaro Nagi and Commander Jack Vandham. The key objectives of B.L.A.D.E are to maintain order, find the survivors of the White Whale who were sealed in stasis in lifepods, and figure out how to ensure that humanity can survive on the planet. The planet is named "Mira" by Chausson, after a crucial member of Project Exodus.

2 months after the crash, Elma finds a single survivor, Cross surrounded by destroyed lifepods. She awakens them and begins to escort them out of Starfall Basin, where they had crashed, and back to New Los Angeles. However, soon after their awakening, Cross must fight the Origin Blatta alongside Elma using a knife and assault rifle given to them by the latter. After defeating the Blatta, Elma notes Cross's combat skill, recommending that they join B.L.A.D.E. The pair then make their way to NLA, defeating a pack of Grexes near the entrance as they do so.