All that remained of Mabel was one parting note saying she left Gravity Falls for "various reasons". When many years pass and a pair of lost twins come across the shack, there may just be more to Mabel's "various reasons" than anyone could've imagined.

Trapped and too scared to tell anyone, Mabel struggles to hide her abusive relationship.

Humans are an inferior race in a world ruled by halfas, but they depend on us to keep their species alive. To ensure that halfas will continue to exist, they bring us to halfa factories, where we are forced to create their next generation.