The Chaldea Organization must deal with the Grand Temple of Solomon, the King of Magic, which has come to destroy the world.

The year 2015 CE. The last era in which magecraft still thrived. The Chaldea Security Organization was founded to focus on preserving the continuation of human history. They observe a world which magecraft couldn't observe and science couldn't measure all to prevent the certain extinction of humanity. But one day, the future that Chaldea continued to observe disappears and humanity's extinction in 2017 becomes clear. Rather, it had already happened. The cause seems to be related to Fuyuki, a provincial town in Japan, in the year 2004 CE. There, an "unobservable region" that had not existed before appears. Based on the assumption that Fuyuki is the reason for humanity's extinction, Chaldea issues an order to explore, investigate, and possibly destroy this singularity – a quest for the Holy Grail, the Grand Order.

The Lostroom. A place where you can see what was lost, or maybe what will be lost to you in time. Existing in the innermost part of Chaldea, it is the boundary line between dream and reality where the light of the Moon shines through. Produced by the Chaldea Summoning System, the room holds a small number of worthwhile benefits to enjoy.

The characters who appear in "Fate/Grand Order" are heroes from myth and legend, and your encounters with these Servants weave an entirely new tale. “Myth and legend merge into a tale of your own.”

The Humane Continuity Guarantee Agency, Chaldea, observes a world that can not be seen only with magic. One day, the near future observation lens Shiva will incinerate the future of humanity in 2017-it has been proven that humanity will be extinct. "Unobservable areas" suddenly appearing in various places in history-singularities. Chaldea assumes this is the cause of human extinction and decides to travel in time to the past. Members of Chaldea, such as Tatsuka Fujimaru, Mash Kyrielight, Leonardo da Vinci, Romani Archiman, intervene in singularity events, A forbidden ritual to elucidate or destroy this-the name is being searched for “the Holy Grail (Grand Order)”. The wise king Gilgamesh dismantled Babylon and rebuilt it as a fortress city, Babylonia, to stop the onslaught of evil beasts. Gods, beasts, and humans. The battle for the survival of the species has now begun.

Tasked with preventing the destruction of humanity, the Chaldea Security Organization observes an anomaly: the Near-Future Observation Lens: Sheba proved the extinction of humanity in 2019. Chaldea pinpoints space-time Singularities thought to be the cause of humanity’s extinction and executes a forbidden ceremony called Rayshifting, where mages are converted into Spiritrons and sent into the past to restore humanity. Under the command of Romani Archaman and with the aid of numerous Servants, Ritsuka Fujimaru and Mash Kyrielight begin by restoring Singularity F: Flame Contaminated City, Fuyuki. From there, they make their way through seven Singularities, resolving each of them. And now, the path to the Final Singularity, Grand Temple of Time: Solomon, lies open, and the final battle against the King of Mages is underway.