Little Egg, Big World jumps through time, examining different moments in Little Egg's/Grown Uterus' life. Along the way, they sort the unsortable thoughts with a host of real and imagined characters from parents, to geneticists, to other eggs in utero. As Little Egg searches for her father and Grown Uterus tries to come to terms with anonymous donation, the two navigate through trials of identity, abandonment, betrayal, curiosity, love, and discovery.