In the midst of the tumultuous Fourth Holy Grail War, the Servants and their Masters receive a summons from Church overseer Risei Kotomine to unite against a looming menace jeopardizing Fuyuki City. What starts as a fragile alliance crumbles swiftly, revealing Masters' ruthless resolve to claim victory at any cost. Tensions rise as Kiritsugu Emiya and his devoted Servant, Saber, clash over their beliefs in heroism and honor. Simultaneously, a mysterious connection blossoms between Kirei Kotomine, still in search of his life's purpose, and a formidable Servant. With the war hurtling towards its climax, the distinction between success and failure blurs beneath the escalating price of triumph.