Fate/stay night - Season 1 Episode 17 Mark of the Witch The Holy Grail War Begins!
Overview: Shirou wakes up after having yet another dream of Saber's past and is clearly shaken up by what happened. That morning, during breakfast, Ilya is introduced by Rin as another person to be staying there for a while and Taiga seems to accept it well. Meanwhile there have been news on even more gas leaks, meaning that the Master at Ryudouji seems to be escalating his plans. While Shirou, Rin and Saber are planning what to do about this, Ilya enters the room with a great deal of information on this topic.