The novel begins in prison, with the novel’s protagonist and narrator Oliver Marks handcuffed to a table and talking to Joseph Colborne, the detective who was formerly assigned to his case. Colborne congratulates Oliver on being granted parole after serving a ten-year sentence for the murder of his classmate, Richard Stirling, and asks him to share what actually happened ten years earlier. Oliver agrees and the narrative shifts in time to a period ten years earlier. At the start of each chapter, called “acts” as in a play, the novel returns to the present, where Filippa drives Oliver to Dellecher Classical Conservatory, the prestigious arts school they attended together. Detective Colborne and Oliver walk around the lake, reliving and narrating the events that led to Oliver’s incarceration.

The novel’s main action revolves around  seven fourth-year acting students. Their final year will focus on Shakespeare’s tragedies, and their fall performance is slated to be Julius Caesar. Close friends, they can easily anticipate their roles based on previous castings, even before their auditions: Richard will be Caesar; James will play Brutus; Alexander, Cassius; Oliver will be Octavius; Meredith’s role will be Calpurnia; Wren will play Portia; and Filippa will be in drag, playing multiple male characters. The students are also assigned roles for a Halloween performance of Macbeth

In response to pressures of their fourth year, previously close relations between the students quickly devolve. Richard begins abusing his classmates, physically and verbally, during rehearsals for Julius Caesar. His girlfriend, Meredith, and his main competitor, James, are both covered in bruises. Tensions run high as the play is slow to come together and, after the Macbeth performance, a friendly game in the lake turns ugly when Richard holds James under water, nearly drowning him. Meredith breaks up with Richard, and the group decides to teach him a lesson, using a rehearsal to attack their classmate. But despite obstacles, the play finally comes together, and opening night is a success. At the raucous afterparty, Meredith flirts with a cellist and Richard, enraged, attacks him, sending him to the infirmary. Angry, Meredith invites Oliver up to her room, and the two have sex, while an enraged Richard pounds on the door.  

A few hours later, Filippa summons Meredith and Oliver to the lake. There Oliver and Meredith discover a battered, broken and seemingly deceased Richard floating in the water. Richard emits a gurgling sound indicating he’s still alive. Frightened and exhausted of Richard’s abuse, the six collectively decide to let him die in the water, assuming that he injured himself while intoxicated. They craft a narrative of likely events for school administration and the police and feel relief when everyone seems to accept their version of events. But guilt erodes their relations with each other and impacts their behavior. Meredith and Oliver continue dating but struggle to be comfortable together under the watchful eye of Richard’s specter. Alexander indulges even more freely in drugs and alcohol. Wren withdraws into herself while James’s behavior becomes erratic. The only character who seems able to hold things together is Filippa. The Thanksgiving holiday offers little respite from their stress. When Oliver’s holiday plans to visit Meredith in New York are derailed by an unexpected visit from James, Meredith is upset that Oliver chooses James over her, a frequent point of contention. 

The Christmas holidays prove equally tense. Oliver learns that his family cannot afford for him to return to Dellecher and, after fighting with them, flees to New York, spending the break in Meredith’s family apartment. Oliver arranges for financial aid to complete his final year, agreeing to be the custodian for the Dellecher Castle, where the acting students live. The play for the spring is King Lear and, unlike the fall, the casting comes as a surprise. James is assigned the role of Edmund, the play’s main antagonist, while Oliver, usually cast as James’s sidekick, is given the part of Edgar. The two friends are now opponents. Not only do the teachers, Frederick and Camilo, take roles to fill out the mature cast, but James and Meredith also have romantic scenes, a challenge given their mutual dislike. The students will also perform Romeo and Juliet as a masque. 

When the police return and Alexander overdoses, Oliver realizes the group is beginning to crack under the strain of allowing Richard to die. While cleaning the fireplace, Oliver finds a bloody piece of cloth, clearly from Richard’s shirt, and realizes that his death was not the accident they believed it to be. Oliver hides the fabric but feels mounting anxiety. At the same time, rehearsals for King Lear add drama to the students’ lives. Prompted by Gwendolyn, who deplores their lack of connection, James and Meredith kiss passionately. Watching, Oliver realizes he is jealous and comes to understand that he has feelings for James. During another rehearsal, this time for a fight scene, James attacks Oliver, breaking his nose. They limp through the Romeo and Juliet performance, their relationships fragile and tense, although King Lear proves their final undoing. 

The day of the performance, while cleaning, Oliver finds a bloody boat hook hidden in James’s mattress and realizes that he must have used it to hit Richard. Oliver confronts James, who admits that he did hit Richard with it after Richard bullied him and accused him of being in love with Oliver. James also explains that Filippa has known the truth all along and helped him hide the crime. Despite these revelations, Oliver and James manage somehow to finish the play. The detectives and school administration wait in the wings. After the play, Oliver confesses to the crime James committed. Though Detective Colborne is suspicious of his confession, Oliver doesn’t recant it, and after a brief trial, Oliver is charged with second-degree murder. Oliver’s story finished, the novel ends in the present. Colborne wishes him well, and Filippa, who has visited Oliver every two weeks during his time in prison, informs him that James committed suicide years ago. Oliver goes to New York to see Meredith, now a famous actress, and the two resume a relationship. Filippa sends Oliver a note James had left for him, which is a passage from Pericles, Prince of Tyre. The passage is obscure but leaves open the possibility that James, whose body was never found, may still be alive.