Fate/kaleid liner Prisma☆Illya 3rei!!

Illya's fun summer break comes to a sudden end. The aftermath of their battle against the Heroic Spirit of the 8th Class Card disappeared overnight from Mt. Enzou. Their suspicions aroused, Illya and the others race to the scene, where they encounter two mysterious women who say they've come to retrieve Miyu... After a fierce battle, they're all bathed in a mysterious light. Afterwards, Illya wakes up to a midwinter Fuyuki City?!

One of Ainswoth's dolls, Beatrice, attacks Illya and the mysterious girl, Tanaka. Both are driven into a corner by her overwhelming strength. Just as they run out of options, someone calls Beatrice back, freeing them from their peril. Afterwards, they both fall victim to hunger and a suspicious ramen shop owner gets them into an even worse crisis--they don't have money to pay him! But the one who saves them from those straits is who you'd least expect.

Led by Gil, Illya and Tanaka successfully infiltrate the Ainsworth mansion. Their goal is the room where Miyu's held captive, but standing in their way is Beatrice and Angelica. When she's driven into a corner, Illya manages to reunite with Magical Ruby, regaining her power as a magical girl, and taking a stand to save Miyu!

Thanks to sniping from Kuro, Illya's group managed to slip away from Beatrice and retreat from the Ainsworth mansion for the time being. Then they try to regroup at the school building Bazett and Kuro and have been using as their base. However, Illya couldn't figure out a way to counter their Cards: Archer (Gilgamesh), and Berserker (God of Thunder, Thor), leaving her dejected. Seeing her like that, Kuro suddenly turns her twin swords at Illya and attacks?!

Bazett's barrier was supposed to prevent surprise attacks from the dolls, however Illya finds a little girl, Erica, sneaking into their school. For some reason Erica calls Illya "Onee-chan", and the two of them quickly hit it off. Meanwhile, a man claiming to be Erica's father appears. He seems kind at first glance, and while he came to pick up Erica, he's also...?!

The man who came to pick up Erica proclaims himself as Darius, head of the Ainsworths and Miyu's kidnapper. Using his great power Darius activates an ice-barrier Noble Phantasm. Even with Kuro's Caladbolg, their attempts to break the barrier barely scratch it while Darius delivers a shocking statement to Illya!