Betonie the medicine-man is a very important character in Ceremony. He tries to cure Tayo of his physical and cultural malaise by inducting him into a special ceremony. The physical illness from which Tayo is suffering is accompanied by a spiritual sickness. As well as his physical ailments, Tayo is also suffering from a spiritual malaise caused by the curse he made upon the rain. When Tayo made the curse, he unwittingly bewitched his ancestral lands, and now only an ancient Navajo ceremony can make things right again.
Betonie instructs Tayo in what he must do as part of the ceremony. He must find the speckled cattle that wandered south once Tayo's uncle passed away. Once embarked upon his epic journey, Tayo also has to encounter all the other things depicted in the sand painting made by Betoine as part of the ceremony: a pattern of stars, a mountain, and a woman. The ceremony to restore Tayo and his land back to health will not be complete until Tayo has encountered all of them.
Betonie acts as the catalyst for Tayo's epic quest. But it is Tayo himself who must encounter what's in Betonie's sand painting and bring back the heard of errant cattle to his ancestral homeland. Betonie can certainly give advice, but it is ultimately only Tayo who can take the necessary steps to complete the ceremony and lift the curse.