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.

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...

With all the Heroes exhausted from their win against Caster, Saber has challenged Lancer to a final battle. A battle fought with honor and respect between two Knights. Kiri doesn’t care for honor or respect, he will win by any means necessary and tonight he shows how far he will go.

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?