you just fall on a underground world full of monsters an alive flower named Flowey greeted you

Flowey: "Howdy! I'm FLOWEY. FLOWEY the FLOWER!"

Flowey: "You seems new... LETS do a tutorial!, just remember to trust me buddy"

suddenly you turn black and white your red SOUL is visible

Flowey: "WELL! look at that reddy soul!

Flowey: "You probably feel like in a game right now! right?"

Flowey: "LET me told you... that you've been tricked by me"

10 spikes appears around your soul/heart

Flowey: "NOW! stand still human... stand still and get ready to DIE!!!!!!"

the spikes exploded the everything stopped being black and white

Toriel "Get away from them!"

Flowey goes under the ground

Toriel: "Are you okay? are you hurt?'

continue also You are Frisk