After some time after Frisk's disappearance, Skylar (Frisk's sister and Ambassador's Assistant), Gaster (to the two ladies' ignorance), and Alphys finally receive a clue as to their whereabouts through a phone call...in which it seemed as though Frisk was saying their final good-bye to her.
Alphys pinpointed the location where the phone call came from, and Skylar, filled with Determination, ran to the place. While she ran, Alphys called every one of Frisk's friends and told them what happened. Other people who saw Skylar followed her.
Once there, Mettaton tried to fight off Gaster, only for bats to appear.
A nearby Temmie's death caused Skylar to discover her ability to Save and Load. After managing to calm things down, the group learns that Frisk went to the Underground and they seem to not want to be found. Everyone decides to split into two groups: One goes to the Underground and the other stays on the surface.
