Nulltale - Story Summary
Nulltale is an Undertale AU in which Frisk and Chara share control over Frisk's body, continually run the genocide route, and reset the timeline thousands of times. Just as their interest in resetting the timeline was about to falter, the file started corrupting, changing little bits and pieces here and there. Each time the human reset, something would change, either temporarily or permanently. For their own amusement, the human continued to reset the timeline, purposefully tormenting the monsters of the Underground, some of which were affected physically, mentally, or both by the corruption.
Sans does everything he can to stop the human and their vicious cycle, but the resets were beyond his control. He becomes corrupted, losing his right eye, becoming incompatible with most of his own magic, and scarring him with a permanent hole in his chest, all as a result of clashing against human. Driven to despair after many thousands more resets, Sans starts to overflow with the negativity that wells inside of him, tar-like goop seeping out of his right eye and chest hole. During a battle with the human, Sans reaches one of his lowest points and becomes consumed by the concentrated negativity he cannot control, slipping him into cold, goopy realm.
After what seemed almost 100 years, Sans eventually learns how to control the goop within that realm and escapes, returning to the same spot in the Underground where he'd last fought the human. Sans discovers that approximately 4 years have passed and monsters and humans now lived on the surface together in harmony. Sans makes it his mission to find the human and confront them while figuring out his place in this timeline.
