Healer of the water monster

"When Nathan goes to visit his grandma, Nali, at her mobile summer home on the Navajo reservation, he knows he's in for a pretty uneventful summer, with no electricity or cell service. Still, he loves spending time with Nali and with his uncle Jet, though it's clear when Jet arrives that he brings his problems with him. One night, while lost in the nearby desert, Nathan finds someone extraordinary: a Holy Being from the Navajo Creation Story--a Water Monster--in need of help. Now Nathan must summon all his courage to save his new friend. With the help of other Navajo Holy Beings, Nathan is determined to save the Water Monster, and to support Uncle Jet in healing from his own pain"--From the publisher's web site.