Kairi Sisigou is summoned by Rocco Belfeban, who reveals that Yggdmillennia has gone rogue. To obtain the power of the Holy Grail, the Clock Tower begins a new War between Yggdmillenia and the Tower.
Jeanne d'Arc is summoned as a Servant and is ordered to make sure the War proceeds as ordained. Each of the masters greet their Servants, with Sisigou introducing himself to Mordred.
The battles between the Servants begin. Karna attacks Jeanne only for Siegried to intervene. Caules talks with Frankenstein's monster as Chiron heals a Homunculus.
Spartacus continues his attack on Yggdmillennia's castle. The Black Faction mounts a counterattack as the Red Faction sends more of it's own soldiers. Jeanne supervises the battle.
The Homunculus named Sieg awakens only to be caught in the middle of a battle. The Black Faction retreat when Jeanne intervenes and elsewhere Jack the Ripper goes on a rampage.
The fight between Caules and Mordred ends in a draw. As various Servants follow their own objectives, Sieg begins to question the nature of his own existence.
The Red Faction begins their attack on Castle Yggdmillennia as Shiro appears on the Hanging Gardens to fight himself. Loyalties are tested and alliances are offered as all out war continues.
The battle for the Holy Grail rages on as members from the Red and Black Factions start fighting head to head. Elsewhere, Darnic holds the Holy Grail and remembers how he stole it.
Atalanta leads forces into battle in the aftermath of several Noble Phantasms clashing at once. Some Servants are forced to retreat while others are only more fired up to continue fighting.
Darnic unleashes his final gambit, using his spells to turn Vlad into his ultimate form. The remaining Servants decide they need to put aside their differences to stop their overpowering foe.
Shiro now possesses the Holy Grail and announces his plan to save humanity. Lines in the sand are drawn as Servants need to decide whose side they are going to be on when Shiro begins his plan.
The Hanging Gardens fly away and Jeanne affirms Sieg's choice to officially enter the Holy Grail War. A powerful golem marches on the castle and the Servants must assemble to face it.
Achilles, Atalanta, and Karna reluctantly work with Shiro in order to rescue their captured Masters, with each of them having their own objective. Shiro reveals to Mordred why he wants the Grail.
Sieg is slowly transforming into Siegfried himself, which is taking a toll on his body. Despite Jeanne's concerns, she and the others need to deal with Jack the Ripper, who has gone on another rampage.
The group heads into Trifas to face Jack the Ripper and their mysterious Master. In the Hanging Gardens, Achilles has a conversation with Shiro about what he wants to do.
