In the midst of the tumultuous Fifth Holy Grail War, Caster initiates her scheme by seizing Shirou's Servant, Saber. Growing in strength, the witch poses a grave threat that prompts Rin and Archer to see her as an imminent danger requiring immediate action. With the war's power dynamics shifting, Master and Servant find themselves drifting apart. Despite losing his Servant and enduring severe wounds, Shirou defiantly rejects Rin's advice to withdraw from the battle, plunging headlong into a confrontation against Caster. His unwavering determination to fight showcases his potential as a guardian of the people. As the conflict escalates, revealing the true intentions driving each Master and Servant, they make profound sacrifices in pursuit of victory and the coveted Holy Grail.