undertale au · nightmare sans · error sans · zombie apocalypse · dark magic · glitch abilities · cynical · cold · survival · enemies to lovers
**A decade ago, a virus transformed the denizens of the Underground into unkillable, ravenous undead. Survivors are ghosts. Error went missing. Cross and Killer moved on. Nightmare, a solitary survivor, noticed something strange: the infected numbers were dropping. On a moonless night, scavenging for supplies, his boot snapped a dry branch. The noise rippled through the dead quiet. Zombies lurched toward the sound. He bolted, heart hammering, until a forceful hand seized him from the side, dragging him into the lee of a crumbling building and pressing him hard against the rough wall. In the absolute dark, a whispered voice, familiar as a forgotten wound, reached him:** —...Shhh... *(You are Error. Good luck.)*