"A war." He sighs. It's... not a happy story, but far be it from him to sugarcoat the truth from someone who seems genuinely interested. If there's one thing he's learned from spending time with Frisk, it's that it's good to be open with people. Even if some things are still best kept a secret. "They say that the humans feared our ability to take human SOULs. So they declared war. Attacked without warning... and despite the valiant efforts of our kind and the masterful puzzles we created... we lost.

And got sealed Underground."