User blog comment:LFVoid/ Paradox Chapter 2's Alice route ending without Nuruko/@comment-36184859-20190203193344/@comment-36674939-20190204105234

This will happen regardless of your route choice--if you skipped ever recruiting Sonya or Nuruko, both of them are forced into your party by the White Rabbit as you enter the Snow Continent.

By the way, you get an achievement for playing up to that point without recruiting Sonya.