‘One of Us Is Lying’ on Peacock: Who Killed Simon?

Who doesn’t love troubled teens and murder mysteries? That’s the combination Peacock is counting on with its newest original series, One of Us Is Lying. If you haven’t been active in the world of young adult thrillers, there’s a chance you may have missed the hype around this title when the novel was first released. We get it, and we’re here to help. Heading into Peacock’s premiere of the first three episodes of its new original series, here’s what you need to know.

One of Us Is Lying was released in 2017 as Karen M. McManus’ debut novel. The book almost immediately took off. It became a New York Times bestseller, spending an impressive 166 weeks on that list. It also became a USA Today bestseller, an Entertainment Weekly Best YA Book of the Year selection, a Buzzfeed Best YA Book of the Year selection, and a New York Public Library Best Book for Teens selection. That near instant success isn’t difficult to understand.

The best way to describe One of Us Is Lying is as a cross between an old-school murder mystery novel and The Breakfast Club. Set at the aggressively stereotypical Bayview High, when the novel begins life is as stressful and clique-filled as the average high school. The book jumps between the perspectives of four students: Bronwyn (Marianly Tejada), the overachieving Ivy League hopeful; Nate (Cooper van Grootel), the local bad boy who’s currently on probation; Addy (Annalisa Cochrane), a popular girl who is defined by her relationship status; and Cooper (Chibuikem Uche), a baseball player who moved to Bayview to better his recruiting chances. On the first day of school, they’re all given detention after four cell phones they’ve never seen before go off in class. They’re joined in their punishment by Simon (Mark McKenna), the creator of the school’s gossip blog and app About That.

While their teacher is distracted, disaster strikes. Simon collapses on the ground after drinking from a cup of water that’s been contaminated by peanut oil. The suspects? Bronwyn, Nate, Addy, and Cooper. The crime? Murder.

The book as well as the series asks the audience to figure out who ultimately killed Simon. As the series unfolds, it becomes clear that every one of these students had a reason to hate their local gossip blogger. They all had life-ruining secrets they wanted to protect and that Simon happened to know. The story pieces together who did it while also documenting the downfall of each student as their lie is revealed.

Who Killed Simon in One of Us Is Lying?

Of course, there’s always a chance that Peacock’s adaptation will have its own twist. But if you want spoilers, oh do we have spoilers.

First things first, let’s get to the big secrets in everyone’s court. According to the book, Bronwyn cheated on a test that could affect her college admission chances. Addy cheated on her controlling and super popular boyfriend, ruining the illusion that they were the perfect couple. Cooper is gay, a secret he kept from his family and to not upset his baseball recruitment chances. The only one who’s more or less innocent of a clear motive is Nate. Other than general anger at always being at the center of About That, the criminal of this story is ironically the least guilty party involved.

So who killed Simon? The answer is… Simon. He planned to end his life but wanted to do so in a way that was guaranteed to bring down the biggest hypocrites of Bayview as well as the people he believed wronged him the most. Simon worked with Addy’s ex-boyfriend, the vengeful Jake, to execute his plan. All of the evidence for Simon’s death was supposed to be planted on Addy, making her the most likely suspect in the eyes of the law. But at the last minute, Simon’s friend Janae, who slowly becomes friends with Addy, planted the evidence on Nate instead, a decision that led to the collapse of this entire plan.

It’s always possible that Peacock may change this ending. So far the streaming service has added more LGBTQ+ couples to Bayview and has established that Cooper’s girlfriend Keely knew he was gay, two significant changes from the book. Assuming there will be more departures from the source material, it’s entirely impossible the ending will surprise us.

Watch One of Us Is Lying on Peacock