In this episode, Saber, Lancer, Rider and their masters are trying to figure a way out to try and stop Caster (in this tentacle-like thingy) from reaching land and attacking innocent civilians who know nothing about what they're doing and what's happening.
Meanwhile, Kariya, the guy with white hair and blood on his face got owned by Tokiomi and I don't know what was Kirei's intentions to save Kariya and heal him. Perhaps Kirei wants to use him. This whole thing is a battle of life and death anyway.
In the end, with some teamwork, Saber, Lancer and Rider with the help of Waver (Rider's master), Kiritsugu (Saber's master) and his wife Irisviel (White-haired and red-eyed mademoiselle), they managed to kill Caster. Caster remembers his first love Joan of Arc before dying. In mythology, Caster was Joan d'Arc's fighting partner/companion and friend and somehow got crazy after she died.
In the next episode premiere, Lancer is going to be forced by his master to kill Saber. The two would make such a good couple! But all this friendship circle is coming to an end! How sad!
The animations are getting pretty good too! Loving the new opening and ending song!