you'd fall into the underground, as you do you were knocked out, unconscious. you'd wake up, on golden flowers in the underground. though someone was there; a goat figure with a purple robe.

the goat figure noticed you. "E-Eh ..!? I didn't expect you to wake up,...sooner or later. anyways... I'm toriel. ex-queen and caretaker of the undergrounds. who are you young child?"