Blinking he stares at the creature with the human face.
Behind those half-closed eyelids, he sees brown eyes peeking; just then he notices a flash of red.
It all makes sense to him.
Upon the skeleton's eternal grin, a true smile makes its way there.
Sans wants to laugh at himself for not seeing the truth long before now.
Suddenly he knew what the future meant, for not just himself, but dusted brother.
'don't say i didn't warn you...' Sans told them, painfully moving out of sight of the so-called human, not wanting them to view his strange soul when it, at last, gave out.
Blinking they were gone.
He felt the power drain their determination from his bones. Sans allows himself to fall against the pillar that lined the Judgement Hall, darkness overtakes him, he utters some final words before his world ends.