Petra is a 13-year-old girl of Hispanic descent living with her parents in the southwestern United States. She was born with a condition called retinitis pigmentosa that limits her peripheral vision. While both her parents are scientists, Petra is much more interested in the arts and wants to become a storyteller, or cuentista, like her grandmother, Lita.

Unlike all the other space travelers in stasis on their way to Sagan, Petra doesn’t fall completely asleep and retains her memories of who she is. As a result, she is the only person on the ship who has maintained a personal identity. She is eager to restore the memories of her human shipmates and tries to do so by telling them traditional cuentos that she varies to suit their new circumstances.

Petra is brave enough to risk her life to save the other humans on board. She also uses her downloaded programming in botany to try to save the colonists on the planet from a toxin that would kill them. Petra’s desire for grounding in a new land is answered when she leads her band of survivors to a human colony on Sagan and can introduce her stories to this new world.