蠢動
Shundō
Writhe

Saber confronts Shirō over not summoning her against Rider. After discovering that Shirō can detect magical spells related to the force field at school, Rin and Shirō set out to destroy most of them. However, at the end of the day, Shirō discovers in the dojo at the school a very large magical seal and finally finds out who Rider’s Master is.