Back in the Depths

3 days since the Roaring was averted thanks to Asriel returning to Hometown in time.

3 days since the Grand Fountain was sealed, and Ralsei with it.

3 days since the Fun Gang, with the help of Asriel and his knowledge about Dark Worlds thanks to his adventure in the Bunker's dark Fountain with Dess years ago.

3 days since Undyne was found, battered and wounded but still alive, and Alphys disappeared in thin air, after the Roaring.

2 days since the substitute, W. D. Gaster, arrived at school.

But still, no Dess, until now.