After Frisk and Asriel think everything is going to be okay, Chara emerges from the underground. Frisk and Asriel and their friends have to stop a revolution that Chara would bring. Will they survive? Or will they die trying?

Just as Frisk is getting settled on the surface. She starts having night terrors of Asriel and Chara. She packs her things and heads into Mt. Ebott to find him. When Frisk retrieves him and brings him to the surface they live a happy life and their romance grows stronger and stronger. With their friends and family behind them, nothing can go wrong.... Right?