A broken golden flower named Flow pops out of the ground in front of Mystery, Sans, and Chara.

Flow: You guys need to help Asriel! Please!

Mystery: *growls* Why should I help him? He tried to kill me!

Flow: ... That wasn't really your brother. Didn't you see his eyes?

Mystery: Yeah, duh.

Flow: When he tried to hurt you, what color were his eyes?

Mystery: Yellow.

Chara: ... but Asriel's eyes are green, not yellow!

Mystery: It was black, with yellow surrounding it.

Flow: *sigh* I knew it. He already got to him.

Sans: What do you mean? Who are you? Who got to him?

Flow: Asriel's been kidnapped by Fallen. He swapped shirts with Asriel, so that you'd think he was your Asriel... He isn't. My name is F-Flowey... Flowey t-the f-f-flower... but y-you can c-call me Flow. Fallen did.

Chara: What do you mean, "our Asriel"?

Flow: If you must know... Fallen is Underfell!Asriel.