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.

The rules of the game have changed and the Masters have a chance to earn an extra command spell. All they have to do is find Castor and kill him.

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, Saber, and Archer sit down for a drink and discuss what makes a King. The talk turns to violence when Assassin interrupts…

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.

As a child, Kiritsugu lived on a small island with his father Nori. Nori's magical work with flowers has captured the attention of a local girl.

Natalia has raised Kiritsugu since rescuing him from the island. He has followed her in every step in becoming an assassin. Over the years their relationship has grown to the point of mother and child, so what Kiritsugu does next is…

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

Two heroes, two masters, one grail; a winner will be decided.