Suffocate (An Undertale Fanfiction)

Suffocate is a chilling tale of survival, sacrifice, and the fight against the inevitable. When humanity, driven by fear, unleashes toxic gas into the Underground, they expect the monsters to perish—or turn on each other. Instead, the monsters endure, twisted by the very poison meant to destroy them.

Arianna, a human trapped in the Underground for two years, refuses to abandon those she calls family. With Alphys, the royal scientist, she races to create a cure before the last of monsterkind succumbs. But the Underground is now a poisoned wasteland, where even the air is a slow death.

Among the survivors, Papyrus clings to hope, but his brothers are lost—driven mad by the toxin. As time runs out and the ruins grow more treacherous, Arianna faces an impossible choice. Can she save the Underground before it suffocates under humanity’s fear, or is it already too late?