Two Can Keep a Secret by Karen M. McManus is a middle-grade thriller that embraces the trappings of true crime and high school romance to create an engaging, knotty mystery. Published in January 2019, it is the New York Times bestselling follow-up to One of Us Is Lying and is McManus’s second book.

Plot Summary

Two Can Keep a Secret is a story of two high schoolers told in alternating first-person point of view. The first is Ellery Corcoran, who has moved to live with her grandmother in the small town of Echo Ridge with her twin brother, Ezra, after their actress mother, Sadie, is forced into rehab. Sadie’s identical twin sister, Sarah, disappeared when they were teenagers, and the shadow of that trauma hangs over the family. The other is Malcolm Kelly, an Echo Ridge local whose brother, Declan Kelly, was suspected of murdering his high school girlfriend, Lacey Kilduff. Malcolm’s mother has recently remarried Peter Nilsson, a wealthy and powerful resident of town. The two leads are linked to the town’s sordid, dangerous history in ways that will surprise them.

The novel begins with the twins discovering the body of Mr. Bowman, a high school teacher who was killed in an apparent hit-and-run accident. After being interviewed by an Officer Rodriguez, the twins go to a charity event honoring Lacey. There, Ellery meets Malcolm just as he’s stumbled onto an act of vandalism: Someone in town is threatening to kill again.

At school, Ellery meets the popular girls Katrin (Peter’s daughter and Malcolm’s stepsister), Brooke, and Viv, but she would rather be friends with Malcolm and his best friend, Mia. Suspicious events keep piling up: Declan Kelly has moved back home, as has Mia’s sister Daisy, another old friend of Lacey’s; and more threats are found around town. Ellery, Malcolm and Mia are all driven to investigate for their own reasons. Meanwhile, local media begins reporting on all of the goings on in town, led in part by Viv, who works for the school paper and hopes to get into journalism school.

As Ellery and Malcolm are about to kiss at a party at the haunted house where many of the high schoolers work, they stumble on Brooke, who is drunk and trying to pick the lock on a recycling bin. Malcolm drives her home, and in the morning, she has disappeared. The town goes on high alert. It's revealed that Daisy and Declan are back in town because they are in a relationship, and Daisy, who has been struggling with survivor’s guilt, mentions an unusual bracelet that Lacey had when she died. Ellery picks the lock on the bin and finds what Brooke was looking for: a car repair receipt that points to Brooke and Katrin as Mr. Bowman’s killers.

Ellery and Malcolm meet up on homecoming night, and they finally kiss. At the dance, they find Katrin about to commit an act of vandalism. The next morning, Ellery decides to talk to Officer Rodriguez and discovers that he’s her half-brother. This revelation creates a sense of trust between them, and she shares what she knows. He encourages her to stop investigating, as she’s only getting in the way.

Brooke’s body is discovered, and Declan’s class ring is found planted near the body. While talking to Peter at Malcolm’s house, Malcolm and Ellery learn that Katrin was out of town on a shopping spree the weekend of Mr. Bowman’s death, and the only person who was in town and had access to the car was Peter. As they’re discussing this, Peter returns with a gun and locks them in the basement, attempting to suffocate them with a running generator. Peter has been behind everything, including Sarah’s disappearance, and has been preying on underage women in town for decades and then killing them when they threaten to confess.

Officer Rodriguez rescues them just in the nick of time, and Peter is apprehended. The evidence the kids gave Officer Rodriguez was vital to the police investigation, particularly the bracelet, which was linked to Peter. Katrin’s suspicious behavior stemmed from the fact that she knew her father was involved in Brooke’s disappearance and wanted to protect him; the threats around town are revealed to be the work of Viv, who only hoped to pad out her journalism portfolio. Ellery begins to reconcile with her mother, and she hopes that knowing what happened will help all of them heal and lead more normal lives——but she’s troubled by Peter’s final revelation: he had meant to kill Sadie all those years ago, not Sarah.