Ever since the barrier was broken and monsters rose to the surface once more, Frisk and the others couldn't help but notice something different...specifically...SANS was different. The usual laid-back, wise-cracking skeleton was acting...strange. His smile was forced, he didn't tell jokes, he's deprived of sleep, and he loses temper easily and apologizes profusely for it each time it causes him to lash out. It was no secret anymore. Something was wrong...VERY wrong...but what?