The story is set out in the country where the narrator's new baby brother, Doodle, is born.
Doodle is born with disabilities and health conditions. This makes the narrator, Doodle's older brother, angry and considers smothering the newborn. He is unable to accept his brother's conditions.
Due to Brother's "pride", he decides to teach Doodle to walk, swim, and run. One day, they find a Scarlet Ibis, dead, injured, and disabled. Doodle relates to this bird.
Before Doodle goes to school, they train one last time. Doodle, however, is too tired to continue which makes Brother very angry. A thunderstorm occurs and Brother runs home in the rain while Doodle begs for him to stay.
Brother decides to turn back and find Doodle. He sees his brother lying still and lifeless.
The narrator realizes that his pride has killed his brother. Doodle, similar to the Scarlet Ibis, lies still for his Brother to see.