Board Thread:General Discussion/@comment-31536324-20190117214835/@comment-33883848-20190201152621

"Actually, they meet Flowey when this happens, and Asriel said he wasn't going to the Surface. This means Frisk went back underground to load their save point."

Both do. In fact when you kill Flowey he is in the other side of the barrier. Perhaps he did when he had the human souls