Greg is a 14-year-old teenager living in Harlem who desperately wants to join his local community center’s basketball team, the Scorpions. Because of his struggling math grades, he faces strict opposition from his father. Moody and impulsive, Greg chooses to wander into an abandoned tenement building during a storm rather than go home and study. Despite his initial frustration, he possesses a sharp observational sense and quick thinking when placed in unexpected danger.

Lemon Brown is an elderly, unhoused Black man who wears ragged clothes and has a halo of crinkly white hair. Decades prior, he traveled the American South as a moderately successful blues musician known as "Sweet Lemon Brown." He currently survives by scavenging in the neighborhood and seeks shelter in abandoned buildings. He fiercely guards a personal treasure that he claims to possess, approaching life's hardships with a weary but resilient spirit.

The three thieves are neighborhood men known for their rough behavior and willingness to use intimidation. Having overheard rumors of a treasure, they mistakenly assume Lemon Brown hides a stash of money. They are greedy and disrespectful, casually threatening violence against an elderly man to get what they want, though they possess a superstitious streak.

Greg's father is a dedicated postal worker who takes immense pride in the hard work he put into passing his civil service test. Because he had to drop out of school at age 13, he places a high priority on formal education and academics. He uses his parental authority to restrict Greg's extracurricular activities, utilizing strict discipline in an effort to ensure his son does not squander his opportunities.

Jesse is Lemon Brown's son, raised primarily by his aunt while his father traveled across the South to perform. He grew up with a strong connection to his family's history, eventually enlisting in the military to serve overseas. He values the physical representations of his father's love and legacy.