It was 6 month after Barrier broke, Monsters were freed, Humans got along with Monsters

You were friends with Sans, although it was pretty distant. But one day....

Sans had invited you into his home, it can't be that ba- you got killed... by him... in basement...

Sans then uses blue magic onto your Soul, turning it's color into blue as rips it out from your now dead body it, he then rubs his thumb tenderly onto it's surface as he spoke while looking now at your Soul

Sans: got your heart