20 Phần Hoàn tất Frisk had gone back to Underground to find Flowey and bring him up to the Surface with her. What she didn't expect was to find that her coming back there, combined Flowey's laments, had somehow awoken a certain Fallen Human from death.
Now, she must be able to reform the flower and Chara and stop their plans of Genocide. Chara, however, had begun to feel things other than remorse towards her.