A racially-ambiguous senior in high school, The Tao Jones (T.J.) is the adoptive son of John Paul and Abby Jones and the biological son of Glenda, who disappears from his life when he is very young. As the narrator of the novel, T.J. recounts the events of his senior year in retrospect. T.J. is a charismatic figure who manages to transform a group of misfits into a viable swim team and take on the athletic establishment at his high school.

While T.J. is a natural athlete and highly intelligent, the dominant trait that defines his character is his sense of fairness. His actions in the novel, including his creation of the Mermen and his defense of Chris Coughlin, Kristen Sweetwater, and Heidi Marshall, are all examples of his belief in defending people who have been victimized or who are perceived as underdogs. While his defense of these characters arises from noble motivations, T.J.’s own sense of alienation because of his racial identity and early history at times lead him to make poor decisions or to lose his temper in moments when calm is called for.

T.J.’s character arc in the novel is one that takes him from moral certainty to a more complicated understanding of human nature and of right and wrong.