In a Holy Grail War, Mages (Masters) and their Heroic Spirits (Servants) fight for the control of the Holy Grail—an omnipotent wish-granting device said to fulfill any desire. Years have passed since the end of the Fifth Holy Grail War in Japan. Now, signs portend the emergence of a new Holy Grail in the western American city of Snowfield. Sure enough, Masters and Servants begin to gather... A missing Servant class... Impossible Servant summonings... A nation shrouded in secrecy... And a city created as a battleground. In the face of such irregularities, the Holy Grail War is twisted and driven into the depth of madness. Let the curtain rise on a masquerade of humans and heroes, made to dance upon the stage of a false Holy Grail.
Clan Calatin has arrived in front of the entrance of the hospital in hopes of executing a rescue mission for Tsubaki. However, before them appears Alcides, along with his giant dog. The police force and Berserker confront Alcides, who is intent on slaying Tsubaki after identifying her as an enemy in this Holy Grail War, and one by one Servants begin to gather, as if drawn in by the chaos. And thus, the Holy Grail War in Snowfield plunges into a vortex of mayhem.
Though Archer had defeated Saber, the King of Heroes was also forced to fall when his treasury was sealed off by Philia's intervention. However, before the shifting tides of the battle could be seen through, a massive fog suddenly enveloped the city. The police force, Flat, Hansa, and members of each faction were all helplessly swallowed by the black fog. When Sigma awoke, he found himself in a garden where the girl at the center of the conflict, Tsubaki Kuruoka, was playing with animals.
