In this riveting thriller by Armstrong (the Royal Guide to Monster Slaying series), a shocking act of violence jars a group of teenagers into recovering hidden memories from their past. Ambitious, rule-abiding Blythe Warren, 17, and her friends Gabrielle, Tanya, and Tucker—students at a prestigious private STEM academy—have been close for as long as they can remember. But the teens are stunned when typically mild-mannered Gabrielle vehemently claims that the school's security camera is "watching us. It's always watching." Blythe later finds Gabrielle disoriented and mysteriously drenched in blood near their vice principal's dead body. The quartet are suddenly plagued by terrifying nightmares and misremembered recollections, which reveal a covert plan carried out by adults in their lives that was, it seems, meant to protect them from a traumatizing truth. Through punchy prose, Armstrong explores fascinating questions of personhood, identity, and the role of memory in creating a sense of self. While underdeveloped plotlines leave many questions unanswered, fans of mind-bending psychological thrillers will find a lot to love in this labyrinthine read. Central characters are white. Ages 12–up. Agent: Lucienne Diver, Knight Agency. (Apr.)

Gr 9 Up—High schooler Blythe Warren has a tight-knit group of friends: best friend Gabrielle, bad boy Tucker, Tucker's steely sister Tanya, class president Andre, and track captain Callum, whom she has just started dating. Most of the students at Coeus Prep, including Blythe, are children of employees of Coeus Medical Technologies (CMT), a research lab with tight security. When Gabrielle has a breakdown at school, Blythe goes after her to help. Instead, she finds Vice Principal Meeks bludgeoned to death and Gabrielle covered in blood. Blythe's last memories of the day remain hazy and end with going into the bathroom to listen in on Gabrielle before passing out. Then, on Monday, Blythe is at Meeks's funeral, where everyone says the death was suicide. Emails from the mysterious "Veritas" link to an article about a murder committed by a child and hint that someone in the friend group might be to blame. As events and memories don't line up, Blythe and her friends realize secrets are being kept from them and plot to unravel the truth. This thrilling mystery brings in multiple points of view from the friend group and Blythe's younger sister, Sydney, to provide glimpses into everyone's perspective. With a plot filled with remarkable twists and mystery galore, the characters remain less developed, with hints of diversity in the cast based on character descriptions. Perfect for fans of Karen M. McManus and Holly Jackson. VERDICT A must-purchase rollercoaster ride that will have readers wondering if people and memories can be trusted.—Rebecca Greer