Ep 13. The Final Decision

Shirou Emiya has arrived at the Matou household with his Servant, Saber, to rescue his friend and fellow Master, Rin Tohsaka, who has been captured by her own Servant, Archer. Saber quickly engages in battle with Archer while Shirou makes his way to the basement where Rin is being held. Rin reveals to him the true nature of the Holy Grail War and the ritual behind it. She also discusses the underlying motives of Archer and the true identity of his former self.

As the battle between Saber and Archer rages on, Shirou manages to free Rin and they head back upstairs to assist Saber in her fight. Suddenly, Archer unleashes his Noble Phantasm, Unlimited Blade Works, a powerful reality marble that creates an alternate world where Archer's swords are all present and at his disposal. Saber struggles to keep up with Archer's many weapons but manages to land a critical blow. However, Archer reveals that he has prepared a final move, which will ensure Saber's defeat.

Meanwhile, Rin and Shirou have arrived at the door to Unlimited Blade Works and are preparing to enter. Rin warns Shirou of the dangers within the reality marble and explains that the only way to defeat Archer is to destroy his summoning circle, which is hidden somewhere inside. They enter the alternate world and quickly find themselves facing off against Archer's army of swords.

Saber, on the other hand, has been badly injured by Archer's final move and seems to be on the brink of defeat. In a last ditch effort, she activates her own Noble Phantasm, Avalon. This not only heals her wounds but also strengthens her weapon and enables her to finally land a finishing blow. With Archer defeated, the three Masters are left standing victorious.

However, there is one last challenge to overcome. The Holy Grail War is not over yet and the remaining Masters and Servants are still in the running. Rin and Shirou face a difficult decision in choosing their next course of action. Should they continue to fight or should they give up and forfeit the chance to claim the Holy Grail?

The Final Decision marks the end of the first season of Fate/stay night [Unlimited Blade Works] and leaves fans eagerly anticipating the next installment of this epic tale of magic and destiny.