How do I summarize the ending of "The Scarlet Ibis"?
The final summer of Doodle's life he and his brother were working on making Doodle as "normal" as possible. Doodle's brother forced Doodle to physically push his little broken body to the limit and beyond. Doodle only did it because he wanted his brother to love him, he didn't care about being "normal", he didn't think there was anything wrong with him the way he was and he didn't care what others thought.
On the final day of Doodle's life he and his brother took their little skiff (boat) out right before a big storm rolled in. Once the storm hit, Doodle's brother was shouting at him to reach his goal for the lesson. When they reached the shore they both knew that Doodle had not reached the goal. Doodle and his brother begin to walk home, but all of a sudden his brother begins to run leaving an incredibly exhausted Doodle behind. Doodle called out to his brother, but his brother, hearing him, continued to put distance between the two. He begins to feel guilty and goes back to get Doodle only to find that he has died. A large tree branch which was struck by lightning had fallen and crushed him. Doodle's brother feel terribly guilty and ashamed for how he treated his brother and he reflects that Doodle looks like the scarlet ibis that had died in their yard earlier that year. He looked broken like the bird and he was out of place in life like the bird.