A married couple is forced to reckon with their idealized image of their son, adopted from war-torn Eritrea, after an alarming discovery by a devoted high school teacher threatens his status as an all-star student.
An all-star high school athlete and accomplished debater, Luce (Kelvin Harrison Jr.) is a poster boy for the new American Dream. His parents (Naomi Watts and Tim Roth), who adopted him from a war-torn country a decade earlier, couldn’t be more proud of their son. When Luce’s teacher (Octavia Spencer) makes a shocking discovery in his locker, Luce’s stellar reputation is called into question. However, things may not be as they seem.
Luce Edgar is a track star and model student who was adopted from war-torn Eritrea as a child soldier by Amy and Peter. His teacher, Harriet Wilson, brings to attention a disturbing paper that Luce wrote in the voice of Frantz Fanon, who argued that colonialism could be overcome through violence. She also went through his locker and found fireworks in there. When asked about it, Luce suggests to his parents that Harriet has a habit of stereotyping or singling out students like him to make a point.
Amy learns that Luce was at a party where his ex-girlfriend Stephanie Kim was allegedly harrassed, with Luce’s friends and teammates worrying that information about them could get out. Stephanie tells Amy about what happened, and then goes to Harriet with an accusation that Luce assaulted her. When this is brought to the principal, Harriet and the Edgars meet to discuss this, plus the potential of Luce vandalizing Harriet’s home and harrassing her mentally unwell sister, but Luce has an alibi for his whereabouts.
Harriet’s classroom catches fire after fireworks go off in there. She loses her job, and Amy catches Luce and Stephanie together having sex, which strongly implies they were working together to bring Harriet down since she stereotyped both of them. Despite this, Amy chooses to keep acting like she has a perfect son, while Peter knows better.
The film opens with a shot of a crowded hallway in a high school. A locker is opened, and a brown paper bag with undisclosed contents is placed inside.
We cut to the auditorium where star student and athlete Luce Edgar (Kelvin Harrison, Jr.) is delivering a speech to his classmates, the staff, and all parents. He credits the teachers and parents for his success. Afterwards, he is commended for his speech. His adoptive parents Amy (Naomi Watts) and Peter (Tim Roth) meet his teacher, Ms. Harriet Wilson (Octavia Spencer), who calls Luce “an important example to the school”. On the drive home, the family talks about Harriet, with Amy noting her stern demeanor, which Peter and Luce agree means that Harriet is a bitch.
In Harriet’s class, the lesson involves race laws of the mid 20th century. She notices one student, DeShaun Meeks (Brian Bradley), on his phone during the lesson, and not only does she call him out, but she comments how this subject is “life or death” for someone like him. DeShaun angrily walks out after class, with Luce trying to follow him, but he gets ignored.
Amy gets a call at work from Harriet asking her to meet at school. She shows Amy a paper that Luce wrote for an assignment in which the class was asked to write as a famous historical figure. Luce picked Frantz Fanon, who argued that colonialism can be overcome through means of violence. As Luce was adopted from Eritrea when he lived most of his life as a child soldier, Harriet thinks this is a red flag, and that someone like Luce (ie, a young black man) writing this could get him in serious trouble. To make matters worse, Harriet takes out a bag of fireworks that she says she found in Luce’s locker.
At school in the locker room, Luce catches his friend Corey Johnson (Omar Brunson) getting into a fight with another teammate, Kenny Orlicki (Noah Gaynor), over Orlicki supposedly telling people about something they all did. After the fight is broken up, Corey warns Luce that the situation involves him as well.
Amy brings up Luce’s paper and the bag of fireworks (which she took home) to Peter, but they hope that Luce will be mature enough to come forward with this. During dinner, the family brings up Harriet again. Luce says that she typically singles out some students, including himself, to make a point. For instance, one classmate, Stephanie Kim (Andrea Bang), was alleged to have been sexually abused at a party while drunk, and Harriet often uses Stephanie as an example of a victimized woman. In Luce’s case, he is Harriet’s shining example of a star black student, which is not how he wants to be seen. Peter tries dropping hints about whatever Luce has done, though he doesn’t know what Peter is talking about. Later, while Luce cleans up in the kitchen, he finds his paper and the fireworks in the cabinet where Amy hid them. He knows Harriet is behind this. He finds her on Facebook and sees that she has a sister.
Harriet and Principal Dan Towson (Norbert Leo Butz) arrive for a debate practice where Luce is acting as the prosecutor. During the debate, Luce speaks directly to Harriet, almost as if he is confronting her by bringing up cases about students who were charged with crimes based on the suspicions of the teachers that caught them, and whether or not those teachers should have respected their students’ privacy.
After the debate, Luce talks to Corey about smoothing things over with Stephanie, who is involved in whatever Corey and Orlicki were arguing about. They then notice DeShaun smoking a joint outside, and they mention how Harriet got DeShaun kicked off the team. Luce meets with Harriet in her classroom over the issue of his paper. He acknowledges his wording but defends his stance that he just did what the assignment asked. Before leaving, Luce asks Harriet what her favorite holiday is, and he says he loves Independence Day because of what it stood for, but when he brings up fireworks and makes an explosion gesture, Harriet takes it as a threat and informs Peter about it. He and Amy confront Luce about the comment he made, plus the fireworks being in his locker. He explains that the guys on his track team share lockers, so the fireworks do not belong to him. Peter thinks Luce is lying to them, while Amy is not sure what to believe.
Luce later goes out for a run and ends up going to Orlicki’s house for a moment. They talk about the situation with Corey and Stephanie, as well as Orlicki making a comment that Luce and DeShaun are two different types of black men. Luce goes home to an apologetic Amy, who defends Harriet’s actions as just looking out for Luce.
Luce gets a phone message from Stephanie, who says she wishes they could talk like they used to, but since Harriet referred to her as an example of “a woman suffering in silence”, the two agree to take a break.
Harriet is tending to her sister Rosemary (Marsha Stephanie Blake), who suffers from some kind of personality disorder. The two go grocery shopping, and they run into Luce. He introduces himself to Rosemary and is charming toward her, though Harriet is visibly uncomfortable with him talking to her. Later that night, Harriet finds her home trashed and vandalized, and Rosemary is sitting down after suffering an episode.
At the school car wash, DeShaun gets in trouble for being there until Luce intervenes, saying he invited DeShaun. The two talk about how Harriet got DeShaun kicked off the team after she found weed in his locker. He points out how Luce didn’t get in trouble for it despite smoking as well, because he knows that Luce is like a token for the school.
Amy gets in touch with Stephanie after hearing about her. The two meet in a coffee shop so that Amy can find out what is going on between them and Harriet. Though uncomfortable discussing, Amy convinces Stephanie to tell her story. She tells Amy that she and Luce used to date, which Amy did not know about. Stephanie brings up the party incident – she was drunk and got roped into playing a disturbingly sexist game with other guys where they would pass her and other girls around on their laps, and she would occasionally feel their erections brushing up against her. Luce apparently told the guys to stop and he stayed with her. When Amy asks if Luce was involved in the game, Stephanie insists that Luce wouldn’t do that. As far as Harriet is concerned, Stephanie mentions Harriet talking about her, as well as her searching DeShaun’s locker. She also adds that she misses Luce and that he was the best boyfriend she ever had.
Amy goes home to Peter, and they talk about Luce again. He insists that he loves his son but cannot ignore the fact that he is hiding something. Amy seems to just want to pretend everything is fine. Meanwhile, Luce practices another speech he is preparing to give. He later hears from Stephanie that she met with his mom, and she says they need to talk.
Harriet is giving a lesson when she is called by Towson to go outside. Rosemary is at the school having another episode, frantically yelling for Harriet until she starts to take off all her clothes. Harriet does what she can to calm her down, but Rosemary is taken into custody by police and is tased, even as Harriet pleads with them to cover her up. Some students film the incident on their phones until Towson orders them to hand their phones over. Luce and his parents watch the incident on video at home and are mortified by the way Rosemary was treated.
Harriet is alone at home. She goes through her home and finds a horrible slur sprayed on her window. Stephanie arrives at her house to suggest to her that Luce sexually assaulted her. Harriet takes this to Towson, and Amy and Peter are informed about it. Amy confronts Luce about what he may have done to Stephanie. The three of them go to the school to meet with Harriet and Towson. Harriet doesn’t hold back with her accusations against Luce, especially when asked about where Luce was the night before. He says he was with friends and has a video on his phone to prove it, although he was hesitant to show since he and his friends are shown smoking weed. Harriet then thinks that Luce sent Stephanie to her house to tell her about the accusation. When Harriet brings up the fireworks to Amy, Amy lies and says that she knows nothing about the fireworks, even telling Towson that Harriet deliberately went after her. The meeting is done. The Edgars go home.
Later that night, after the school is seemingly empty, a bunch of fireworks go off in Harriet’s classroom, causing a major fire.
Harriet meets with Towson and is told she is fired due to heavy suspicion against her. After learning of the incident, Amy runs home to find the fireworks, only to discover in horror that they are gone. Peter believes Luce was involved, but Amy desperately wants to believe it’s not true, maintaining her stance with her son.
Luce goes to visit Harriet at her house. She is clearly not happy to see him, but he comes forward to her with how she ruined DeShaun’s athletic career and how she put Luce on a pedestal. Harriet defends her position, but Luce thinks all she did was stereotype them. She orders him out of her house. Outside, Amy follows Luce to a hideout where he meets with Stephanie to have sex with her. Stephanie sees Amy outside the window but doesn’t react. Amy realizes with horror that the two of them most likely conspired to bring Harriet down. When Amy returns home to the spot where she hid the fireworks, Luce returns with a paper bag. Inside is a goldfish that he wants to keep as a pet. The two tearfully hug.
Luce gives his speech at school. He mentions how he was renamed after being adopted, and his parents picked “Luce” because it means “light”. He tells everyone that he is lucky to have Amy and Peter as his parents.
The film concludes with Luce going out for another run, looking more frantic as he runs faster.