While returning home from a trip in the next town, Shirō, Rin, and Saber find themselves inside a magical barrier, and they are ambushed by Caster and several water Golems. Caster reveals she has taken Taiga hostage and threatens to kill her unless Shirō hands over his magical circuits to her. When Shirō refuses, Caster tells him that she knows about the fire that he survived ten years ago, then claims her knowledge of a method to summon the Holy Grail without any further fighting, which can only be accomplished by Saber's mana. Shirō allows Caster to take his Command Seals in order to rescue Taiga, but an ambivalent Saber engages Caster in battle. Shirō uses a Command Seal to stop Saber, allowing Caster to stab her in the heart with a dagger-like Noble Phantasm called "Rule Breaker", which takes Shirō's remaining Command Seals and gives Caster control over Saber. After releasing Taiga, Caster forces Saber to kill Rin, but Shirō is injured while taking the blow. Saber then resists against Caster's magic long enough for Shirō, Rin, and Taiga to escape with assistance from Archer. Regaining consciousness at Rin's house, Shirō finds a jewel. He recognizes it as the same one that had been used on him while Rin revived him after he was stabbed by Lancer during the first battle. Meanwhile, Caster arrives at Kirei's church and demands the location of the Lesser Grail, the vessel for the Holy Grail. When he refuses to disclose it, she has him attacked by Golems. Shirō finds Rin at the top of a skyscraper and tries offering his assistance. However, she tells him that without Saber as his Servant, there is no longer a reason for him to be involved in the Holy Grail War and leaves with Archer. As she leaves, Rin warns him to stay out of the war, otherwise he will die.