As Saber and Lancer continue their battle, Kiri and Maiya continue the search for Lancer’s master. What they discover is shocking…

Battle rages throughout Einzbern Castle: Kayneth's magical mercury sphere versus Kiritsugu's formidable gun arsenal, Saber and Lancer join forces against Caster in the forest, and Irisviel detects a new enemy as she and Maiya make their escape.

Rider is shifting Caster into his Reality Marble to buy some time. He asks the other Heroes to come up with a plan to finish Caster off. A phone call from Kiritsugu gives them a fighting chance, but it comes down to Lancer making a difficult choice.