Fate/kaleid liner Prisma Illya - S04

Illya and her friends have just defeated the heroic spirit sealed in the eighth class card. Now, with summer break winding down, they're eager to enjoy what little time they have left. But their plans are shattered when they investigate a strange incident at Mount Enzō and encounter an impossible figure. After a brief fight, the world around them twists and distorts. When Illya comes to, she finds herself in a snowy Fuyuki City-but not the one she knows. This is a parallel world, the same one where Miyu grew up.