Twelve-year-old Daylan hasn't gone swimming in years, not since he had a frightening encounter in El Naci river with Cihuamichin--a legendary water woman with the power to bring either safety or destruction to his small Mexican community. Daylan often has nightmares about Cihuamichin. At school, he's bullied for his fears of swimming and his social anxiety. When a new kid named Eliam starts at Daylan's school, Daylan is forced to confront feelings that he has about himself, and maybe even get in the water again. But Eliam becomes part of a troublesome crew, joining them as they break the water woman's rules. When they threaten the safety that Daylan and his town desperately need, Daylan must find a way to overcome his fear of the river--and take the plunge.