Space-obsessed 12-year-old Paola Santiago and her two best friends, Emma and Dante, know the rule: Stay away from the river. Pao has been told to stay away for even longer than that, because her mother is constantly warning her about La Llorona, the wailing ghost woman who wanders the banks of the Gila river at night, looking for young people to drag into its murky depths. Pao organises a meet-up to test out her new telescope near the Gila, since it's the best stargazing spot. But when Emma never arrives and Pao sees a shadowy figure in the reeds, it seems like maybe her mum was right...