Bless Me, Ultima doesn't fit perfectly into the stock and standard three-act narrative structure. There's something more cyclical about the way the book unfolds. There's a lot of leaving and returning and then leaving again and then returning. Anaya hammers this cycle home by connecting the book's progression to the changing of the seasons (it doesn't get much more cyclical than that). He's very fond of kicking off chapters with things like "The lime green of spring came one night" (8.1) and "The summer came and burned me brown with its energy" (10.1).
Despite the cyclical nature of the book (and the cyclical nature of Nature for that matter), it's still possible to break down the novel into three acts. If we look at Bless Me, Ultima as a young man's quest to find answers about God and religion and spirituality, it actually squeezes quite nicely into three acts, with a major spiritual discovery or activity serving as the act breaks. Here's what we mean:
Act I follows Antonio as he witnesses the death of Lupito, starts to connect with Ultima, and starts asking the major questions about God and religion that plague him through the book. This first Act shows a young boy who is still quite distant from being a man and who wants to please his mother and his father and stay true to things he's been raised to believe, even as doubts start to crop up in his mind.
But the real challenge to Antonio's beliefs that sends him down a path to embrace aspects of Christianity, the old pagan gods, and the magic of the here and now comes when he first beholds the glory of the golden carp in Chapter 11. Once Antonio sees that wondrous fish, his outlook on the Catholic God of his mother is never quite the same.
The middle of the novel follows Antonio as he tries to reconcile the power of the golden carp and the power of Ultima's cures with the powers of the Catholic God. That turns out to be quite the task. While he still longs to receive answers and understanding from God, his faith continues to be challenged by Florence, Cico, and the things he sees around him.
More specifically, Antonio's belief in God is shaken to the core when he witnesses Tenorio murder Narciso, but he still holds out hope for answers from his first Holy Communion, which tells us that he's not quite ready to chuck Christianity altogether just yet. The act comes to a close in Chapter 19 when Antonio takes his first Communion and no answers come to him. Uh oh.
Antonio, hoping he would be closer to God after Communion, now finds that he has no answers. Once again, his belief in a just God crumbles when he witnesses the drowning death of his good friend Florence. Antonio leaves his home and goes to spend the summer with his uncles where he learns to farm and commune with the earth.
Antonio's stay ends with Tenorio confronting Antonio and telling him he is going to kill Ultima's owl, which will kill Ultima. In the final showdown, Tenorio kills the owl but is killed before he has the chance to shoot Antonio. Act III and the novel end with a final spiritual decision. Antonio's request for Ultima's final blessing and his subsequent burial of her owl demonstrate that he has found a way to incorporate his Christian beliefs into the old beliefs of Ultima.