Swallow the Air takes place in numerous "sections", in which May, the main character and protagonist of the book, explains the ups and downs of her life and lifestyle. When she was young, her mother told her to go down to the ocean, in order to do some late-night fishing. Without returning, she and her brother Billy saw an ambulance in front of the house, and realized that their mother had committed suicide.
Their Aunty, simply referred to as Aunty, is very hurt by this dilemma. She slowly falls into a pit of gambling, out of which she can seemingly not escape. It all started when she won a grocery store lottery, and got many free food items. Then, she thought she should try her luck some more, and bought many lottery tickets and became somewhat of a poker addict.
In her time with bad influences, she also becomes an alcoholic. So much for winning a grocery store lottery. May and Billy, still rather young, hang out by the ocean side a lot in their free time. However, this usually leads to them remembering that horrible night when their mother took her own life.
In eighth grade, May goes for a walk on the beach, which is now overrun with tourists. She meets a group of young male surfers, who also happened to be white. This is the first large event that takes race into account in the novel, considering that May is a young black girl. The boys rape her and abuse her because of the color of her skin.
Things continue to spiral out of control. May's father, who hasn't even talked to her for years, writes her a sorry letter. Billy is now eighteen, and Aunty gets him into alcohol. May meets Aunty's new boyfriend, who forced Aunty's face onto a hot stove because he was mad - so much for a charming relationship.
May tries to find her father, but never actually does. Billy becomes addicted to drugs, and, while spending the night with people the police considered bad, they arrested her too and threw her in jail. She continues her travels, going from ghettos to rich "white" neighborhoods.
At the end of the novel, May sees an construction machine tearing away at the beach. She knows that she could never stop them, but she wonders how she could try anyway. She concludes that it is impossible to stop "progress", but doesn't want them to destroy the memory of her mother by simply tearing "her" beach apart.
