There's no getting around it. The ending of "The Scarlet Ibis" is tragic. It ends with thirteen-year-old Brother "crying" and "sheltering" Doodle's dead body "from the heresy of rain" (4.51).
We combed the Internet for questions readers have about the ending. One of the most popular questions is: What does "heresy of rain" mean? We admit it. This is a hard question. "Heresy," in a broad sense, is something that differs from, challenges, or threatens the popular, or authorized view on a given matter. "Heresy" is most often used in a religious context. We'll give you a famous example.
Maybe you've heard of a fellow called Galileo Galilei (1564-1642). Galileo challenged the belief held by the Roman Catholic Church that the Sun and planets revolved around the earth. The Church declared that Galileo was "vehemently suspect of heresy," and he was sentenced to life under house arrest. Today, though, it's impossible to deny that Galileo was on the right track—the Earth does orbit the Sun, not the other way around. (Side note: the story of what exactly happened with Galileo and the Church is still widely debated, so this is just the gist of it. Read more about what went down here.)
Okay, let's get back to "The Scarlet Ibis." Brother isn't saying that any person committed heresy. He's saying that the rain is heresy. It is the dangerous idea or thought that threatens the norm.
What is the norm, the commonly accepted belief that the rain challenges? Well, the belief that Doodle is alive, that's what. Mama and Daddy certainly assume he's alive. And Brother can't believe he's dead. He imagines that Doodle is a scarlet ibis to avoid the painful reality (check out "What's Up With the Title?" for more on that). The rain has featured prominently in his description of the scene of Doodle's abandonment. The rain is the witness to the truth. It rains on Doodle, but Doodle doesn't move or resist, which proves he is dead. By letting the rain fall on himself instead of Doodle, Brother can shield the truth, or at least put it off for a moment.