The mood of “The Scarlet Ibis” is primarily bleak, with a few lighthearted moments throughout. The story opens with Brother (the narrator) making it clear that he will be sharing a story from his past, noting the decay of early fall and the fact that something big happened “that summer.” The mood here is melancholy, as Brother doesn’t directly state what will happen, but readers can sense his pain and longing. As the story goes on, there are some positive moments mixed in, such as when Brother successfully teaches his disabled brother Doodle how to walk and their parents look on with pride and glee.
At the same time, Brother occasionally treats Doodle with cruelty, as Brother himself recognizes in the following passage:
There is within me (and with sadness I have watched it in others) a knot of cruelty borne by the stream of love, much as our blood sometimes bears the seed of our destruction and at times I was mean to Doodle. One day I took him up to the barn loft and showed him his casket, telling him how we all had believed he would die.
The dark mood in this passage comes through in the way that Brother notes how he has “a knot of cruelty borne by the stream of love” within him, as evidenced by his decision to show Doodle the coffin that their parents made for him when he was born (due to the doctor's prognosis related to Doodle's disability). The story ultimately ends with a similarly bleak and depressing mood, as Doodle fails to overcome his disability in all of the ways that Brother wants him to (such as learning how to run or row) and Brother, out of frustration, abandons Doodle to die in the middle of a fierce storm.