01·Who they are
Who is Mr. Avery?
Mr. Avery is a teacher at Bayview High School who serves as the supervising adult during the after-school detention session that opens One of Us Is Lying. He is introduced performing what appears to be one of the most mundane duties in any school: watching students sit quietly and serve out their punishment. McManus gives him no distinguishing backstory, no memorable personality quirks, and no arc of self-discovery. He is, deliberately, an institutional figure rather than a fully rounded individual — a representative of the school's administrative machinery rather than a person with interiority. His importance is entirely structural: he is the adult in the room when Simon Kelleher dies, and everything that follows in the novel traces back to the detention he assigned.
02·Arc & motivation
What is Mr. Avery's arc and motivation?
Mr. Avery has no arc in the traditional sense. He does not change, learn, or develop across the novel. His motivation is simply procedural: phones were found in students' bags in violation of school policy, and he enforces the rule. There is no malice in his decision to assign detention to Bronwyn Rojas, Addy Prentiss, Nate Macaulay, and Cooper Clay, nor is there any particular insight. He acts according to the rulebook, and McManus uses that very blankness to make a larger point. Institutional authority in the novel is not villainous so much as it is automatic — it grinds forward without curiosity, and Mr. Avery embodies that quality completely. His
03·Connected characters
How is Mr. Avery connected to the other characters?
04·Questions
Questions readers ask about Mr. Avery
What does Mr. Avery do at the beginning of One of Us Is Lying?
Mr. Avery assigns detention to Bronwyn Rojas, Addy Prentiss, Nate Macaulay, and Cooper Clay after phones are discovered in their bags in violation of school policy. His decision is procedural; he acts according to the rulebook with no particular malice or insight. That routine disciplinary action, however, places four unrelated students together in the room where Simon Kelleher will die, setting the entire plot in motion.
Why does Mr. Avery give the four students detention?
Mr. Avery assigns detention because phones are found in the students' bags, violating school policy. He enforces the rule automatically, without curiosity about how the phones got there — a detail that later becomes crucial to the murder investigation. McManus uses his unquestioning, by-the-book response to illustrate how institutional authority operates on procedure rather than understanding.
What is Mr. Avery's relationship to Simon Kelleher's death?
Mr. Avery is the supervising adult present when Simon collapses into anaphylactic shock and dies. He attempts to respond but cannot save Simon, and his eyewitness account of the detention session becomes a key piece of evidence that investigators, including Officer Nadia Santiago, rely on to build the case against the four suspects.
How does Mr. Avery's detention assignment affect Nate Macaulay specifically?
Because Nate is already on probation, being present at the scene of Simon's death is especially damaging to his legal standing. Mr. Avery's routine decision to place Nate in detention — without knowledge of or concern for Nate's legal situation — turns a standard disciplinary measure into a serious threat to Nate's freedom.
How does Mr. Avery's detention decision affect Cooper Clay?
Mr. Avery's detention pulls Cooper away from baseball practice, placing the star athlete in a compromising situation that threatens his carefully managed public image. Like the other students, Cooper is drawn into the murder investigation entirely because of Mr. Avery's enforcement of a school rule, with consequences far beyond what a routine detention should carry.
Is Mr. Avery a villain in One of Us Is Lying?
No, Mr. Avery is not a villain; McManus presents him as an embodiment of institutional indifference rather than malice. He enforces school rules automatically and without cruelty or insight. His significance lies in how ordinary, uncurious authority can set catastrophic events in motion; he represents the school's administrative machinery, not a deliberate antagonist.
Does Mr. Avery have any character development in the novel?
Mr. Avery has no character development; he does not change, grow, or learn throughout the novel. McManus deliberately keeps him flat and institutional, providing him no backstory, personality quirks, or arc of self-discovery. His role is entirely structural: to be the adult authority figure whose single procedural decision launches the central mystery.
What role does Mr. Avery play in the murder investigation?
Mr. Avery's eyewitness account of the detention session and Simon's collapse is included in the official record examined by investigators. Officer Nadia Santiago and other investigators depend on his version of events when building the case against Bronwyn, Addy, Nate, and Cooper. Despite being the adult present, his account does not exonerate the students; it simply confirms the facts that frame them as suspects.