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?

A car screams down the moonlit streets of Fuyuki City, with a very happy-go-lucky Irisviel behind the wheel and a slightly unnerved Saber sitting next to her. The evening takes a bad turn when a mysterious shadow darts in front of them. The person claims to be Saber's loyal retainer, yet Saber has no memory of them...

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.