Prolouge.

Nightmare has corrupted the Tree of Feelings, and doesn't know what to do. Out of pure fear of what his brother would do to him, rather than eating an apple, he runs. He runs until he can't feel his legs anymore. All he takes with him is a bottle of water, a few snacks, his cloak, his notebook and his pen. That's when he comes across a small town called Snowdin, where he meets strange new skeletons who join him on the run, one of which, he think he might be falling for...