Starr Carter lives in the predominantly black suburb of Garden Heights. She also attends an affluent, predominantly white private school, where she dates a popular white student named Chris and plays for the basketball team. One weekend, Starr attends a local house party and runs into a childhood friend named Khalil, who ends up offering her a ride home, which she accepts.
On the way home, Khalil is pulled over by a white police officer for a random vehicle check. He is asked to get out of the car, which he does, but when he opens the driver-side door again to check on Starr, the police officer shoots and kills him, thinking a hairbrush in his hand is a weapon.
The media takes on Khalil's story. Khalil is portrayed as a drug-dealing gang member, while the police officer who shot him is portrayed as a good, decorated cop who had a genuine fear for his life. At first, Starr chooses not to speak up, and she doesn't even tell her school friends, Hailey and Maya—or her boyfriend Chris—that she was with Khalil on the night of his death.
Soon Starr starts to buckle under the pressure of keeping her connection to the story a secret, especially as she feels the fragmentation of her identity: the Starr from Garden Heights, and the Starr from Williamson Prep. When she meets an activist named April Ofrah, Starr decides that she wants to speak up, and gives an anonymous interview on television. The only problem is, Khalil's boss, a ruthless drug lord named King, recognizes her and begins to threaten her and her family for speaking up.
After the grand jury decides not to indict the police officer who killed Khalil, peaceful protests break out in Garden Heights. Starr speaks at the protests, exercising her rights and trying to celebrate the memory of her friend, the fact that his life "mattered." When the police launch tear gas into the crowds, trying to disperse them, violent riots begin.
After the riots, Starr and her half-brother Seven go to the grocery store owned by their father, Maverick, who used to be in King's gang and was only allowed to leave after agreeing to take the fall for a crime King committed. At Maverick's grocery, King throws a firebomb into the store, and Maverick, Starr, and Seven barely escape. Maverick confronts King about the bomb, and his young son, Sekani, holds up a gun, threatening to shoot King, just as the cops are arriving. Starr holds up her hands and stands in front of Sekani, blocking him. King is arrested when members of the community speak up against him.
Starr promises to continue on in her advocacy against injustice, and dedicates her efforts to Khalil and his memory.
