Frisk recites an apology that he plans to present to Sans. However, he is struggling to put together one sufficient enough. Asriel soon arrives in a panic. Frisk learns about Sans' death and the news of his fate causes him to lose a bit of his Determination. Frisk and Asriel then leave to find Alphys and Gaster.
Meanwhile, a somewhat injured Jessica arrives at the city's prison to free Asgore and Papyrus from their imprisonment. She apologizes to Papyrus, who felt what happened to Sans. for what she had done, but he forgives her. In doing so, her grey hair turns blue. Along with Undyne, the four leave the prison.
Frisk and Asriel finally arrive at Gaster’s laboratory to find it a mess; Gaster had lashed out in grief, while Alphys is now cleaning up after him. Frisk then meets Gaster outside, where he tells Frisk about his discoveries. Supposedly, only one Determination soul and one Fear soul can exist simultaneously. Also, they are the only ones that can destroy one another. He told Frisk that fear is something that can be overcome, while determination is not. Frisk, after hearing this, regains some of the Determination he had lost.
Suddenly, Bete activates many amorphous pink masses across the city, which quickly begin to attack every living thing in sight. While Asriel is able to protect Alphys from these creatures with little difficulty, Frisk struggles to destroy even one. Gaster informs Frisk that he is not striking with enough force. One of the creatures takes the form of Sans but is nonetheless vaporized by Gaster. After the creatures within their vicinity are destroyed, Undyne, Asgore, Papyrus, and Jessica arrive. Asriel is about to attack Jessica before Gaster interjects to kill her himself. However, Jessica is protected by Papyrus, who convinces Gaster to stand down.
Gaster teleports Frisk, Asriel, and Asgore to Toriel's school to lend aid. Meanwhile, Undyne heads directly into the city, while Gaster, Jessica, and Alphys leave to enact a plan to destroy Bete.
Bete Noire enters a large room called The Nullifier Room, where they plan to stop her. Gaster enters the room as well, and the doors shut behind him. Alphys and Jessica watch as Gaster engages Bete Noire in combat. For the most part, Gaster holds the upper hand in the fight with a wider variety of abilities and greater power. However, the pink blob-like creatures collect enough souls to the point where Bete is able to use a special technique, Rhabdophobia. In doing so, Bete Noire takes control of Gaster's own powers and uses them against him. She nearly kills him but is stopped by Alphys' and Jessica's arrival.
Jessica teleports herself and Gaster away, while Alphys unveils the second part of their plan. The Nullifier Room has an experimental weapon installed into it, and it would destroy any Human or Monster inside. She protects herself with a shield before the weapon fires. Believing that their plan was a success, Alphys celebrates. However, she is then stabbed through the chest by an unharmed Bete Noire, who reveals that she is neither a Human nor a Monster.
Moments after, Undyne arrives. However, she is put under an illusion by Bete Noire to misinterpret the situation. She attacks and accidentally kills Alphys. Bete Noire then attacks Undyne, and her body begins to crumble. However, she musters enough Determination to transform into Undyne, the Undying in order to fight Betty once more.
Written by deleted on Jul 28, 2022