Book excerpt: Rain, now a 12-year-old, is visited once again by the eagle, but this time in a dream. As Rain sleeps, Sky Heart, the eagle, sings a song to him that ends with the refrain, 'a boy must help us.' In the song, Sky Heart provides clues about strange vanishings on the Medicine Cave Indian Reservation. Thistle, the rabbit, has suspicions that Coyote is behind the disappearance of fossils from an ancient turtle, the sudden evaporation of water from the reservation's rivers, and the ominous absence of a 7th grader from Thunder Rock Middle School. Searching for the meaning of the dream, Rain seeks the help of Boomer (Thunder Cloud), Simon, and Hummingbird. Unknowingly, the four friends are drawn into the coyote's game and the criminal activities of a dangerous fossil poaching ring. Deep within the gullies of Shell Ridge, an escarpment that borders the bed of an ancient sea, Rain follows Coyote to a mysterious cave where he discovers the origins of the reservation's water and confronts the notorious fossil thief, Vernon Smeed -- risking everything to save one that he loves. With his pranks and deceptions, Coyote puts Rain through many tests. The trickster teaches the boy lessons that will last a lifetime, but he, too, learns an important truth -- Sky Heart has chosen well. The great bird has entrusted his messages about health and the wisdom of Native knowledge to a remarkable boy whose strength is founded in the steadfastness of friends and love of family.