Timelines; a word you don't seem to understand after going through a genocide run and sparing Sans before restarting. Now you've restarted, forming lost relationships you forgot you made and forming a stronger bond with the punny skeleton himself, Sans. It seems if you want to find out more you'll have to read. SPOILER ALERT: This does rely highly on the actual Undertale game. If you haven't played it yet or are planning to then I suggest you don't read. However if you're cool with spoilers or have played the game then enjoy! I hope you have a very... HUMERUS time!