Seeking the power of the Holy Grail, something that can make miracles occur, seven different mages summon seven Heroes, and fight until the last man remains--a battle of epic proportions, the Holy Grail War. In preparation for the war, various participants are chosen from all over the globe. Eight years ago in Einzbern Castle in Germany, a girl named Illyasviel is born. Her father, Kiritsugu Emiya, embraces her knowing he will be part of the battle, as well.

Kiritsugu and his daughter Illyasviel stroll through the Einzbern woods. As Saber watches the happy parent and child, she ponders why Kiritsugu has not spoken to her since she was summoned. And in Fuyuki City, the battle ground where the Holy Grail War will be fought, the seventh and final hero is summoned.

All the servants have been summoned and now it is a game of spy vs spy. Who will be the first to take the initiative in Fuyuki City?

Rider suddenly appears just the battle with Lancer reaches its climax, much to Saber's consternation. Undeterred, Rider calls out to the many people observing the fight from within the shadows...but it seems he's not the only heroic spirit drawn in by the battle.

Battle rages throughout Einzbern Castle: Kayneth's magical mercury sphere versus Kiritsugu's formidable gun arsenal, Saber and Lancer join forces against Caster in the forest, and Irisviel detects a new enemy as she and Maiya make their escape.

Rider and Waver make a trip into town, and stop in a bookstore along the way. There, Waver reads a biography on Rider's life and learns why he aimed to conquer the far east. Meanwhile, Caster and Ryuunosuke return to their destroyed base. A conversation with his Master leads Caster to an epiphany, and with insanity in his heart, the mad magician begins casting a certain spell...

The battle against Caster continues as the Heroes have no way of stopping him. Toki is trying to appeal to Archer to use his Noble Phantasm to obliterate the monster. Kiri meanwhile, is planning to destroy the source of the monsters powers.

Rider is shifting Caster into his Reality Marble to buy some time. He asks the other Heroes to come up with a plan to finish Caster off. A phone call from Kiritsugu gives them a fighting chance, but it comes down to Lancer making a difficult choice.

Saber vs. Berserker, Archer vs. Rider, another hero will fall and a secret will be revealed.

As commanded by Kiritsugu, Saber unleashes her Noble Phantasm on the Holy Grail, with a completely unexpected result. Who will end up winning the war?