Ebo, a young man about to leave for basic training for the Vietnam War, kills his pigeons because he knows no one will take care of them when he is gone. He puts off killing one that was a gift from his mother when he was only 9 until last. Rather than think about it, he thinks about his younger sister, Momo, who is now a state ward. She's kept in a home for the mentally disabled and he knows that the trip to the mainland from Hawaii where they live will take him by where she is being kept.

Deciding at the last moment to let his last pigeon fly away for now, Ebo goes to the diner across the street from his childhood home to say his final goodbyes to his friends and neighbors. Back at home, he sees his mother making one last breakfast for him. While clearing the dishes later, he thinks about when he first got the bird and how it is back by the coop and he still has to kill it. It reminds him of when they first built the coop and how his stepdad destroyed it the first night before rebuilding it when Momo goes outside to do it herself. Ebo approaches him to ask for a pair of socks, as only his stepdad has any, but his stepdad misunderstands the question and gives him advice on soldiering. (@Samuel Nicol I'm confused about the chronology in the above paragraph: clarify tenses and make the sentences shorter maybe, to make it clear who's doing what.)

Ebo travels to the beach one last time, partly on a trip for his stepdad and partly as a way of saying goodbye. It reminded him of when he first took his pigeon to the wilderness to see if it would come home. He went with Momo, who had her own bird now as well, but since he wanted to be alone he was mean to her. He abandoned her for a while in his anger, and she got lost, eventually falling into a river. She had a fever when they got home and was eventually taken away to the group home.

Back from the beach, Ebo knows he can't kill his pigeon. His mother comes out just as he's about to scare it away and says she'll take care of it if he teaches her. When he tells her he's going to see Momo on the way, she presses him to take the bird and give it to her. After he is fully dressed and ready to go, his mom takes him to the local grocery store and shows him his real dad, who once worked there.

The plane ride was uneventful, though Ebo was stressed as it was his first time in the airport and on the plane. It took a while for him to find Momo in the home she lived in, but when he did she was excited to see him. They go outside and he shows her the bird, lets her release it and they watch it fly towards Hawaii from the mainland where it will most likely die a watery death.