After getting drunk and falling down a hole, Genderless Child finds themself in an underground world of monsters, following the neutral path of Undertale from entrance to arrival at Snowdin

After Papyrus falls to his death, Genderless Child ventures further, encountering Undyne and Alphys.

Genderless Child travels further, ignoring Mettaton and facing off with Asgore as he finally reaches the exit to the surface.

After their attempt to reach the surface only leads them to Underground Heaven, Genderless Child is given another chance to leave by effectively restarting their journey to the Underground, with the condition that he doesn't kill anyone this time.

Still trying to stick to pacifism, Genderless Child "befriends" a few Underground residents, hanging with Undyne, Napstablook, and a snail.

Genderless Child is questioned on their actions so far by Sans and Papyrus; Hangs with Alphys at a dump; And finally reaches a point to progress in the story.

Genderless Child enters Alphys' lab and sees what experiments she made; An awkward meeting with Onionsan

Genderless Child is congratulated for not killing anyone, as he finally reaches Asgore again to hopefully leave the Underground.

Months after leaving the Underground, Genderless Child is forced to take part in a game show by Flowey involving murdering residents of the Underground, with the life of Lad put on the line.

Genderless Child continues the game show, facing down Lad's Wife (Posthumously) and Napstablook via rap battle.

As Genderless Child continues his death spree, they become increasingly concerned about a new malevolent personality forming.

Genderless Child is given an update by Flowey; Papyrus goes on a (useless) journey of self-discovery; And an annoyed, decorated local of Snowden gets help some violent help from Genderless Child.

Genderless Child gets stuck racing against Doggo and David, before going on a spree of mayhem against some of the monsters in Snowdin

Genderless Child's death spree continues, with a brief meeting with Flowey to check up on him.

Flowey expresses concern over Genderless Child's increasingly violent behavior; And Genderless Child gets a visit from Toriel after her betrayal.

Genderless Child's murders becomes full-blown genocide as he goes beyond the game show's rules and starts killing everyone, to Flowey's shock and dismay.

In the series finale, Genderless Child's genocide reaches it climax as he goes after the last few monsters of the Underground.