THE DELTA CODEX, by Deva Fagan, Atheneum Books for Young Readers, April 14, 2026, Hardcover, $17.99 (ages 10 and up)
A girl whose subconscious contains dangerous ancient knowledge finds her voice in The Delta Codex, by Deva Fagan.
Is there safety in silence?
In the city of Danak-Tol, children known as codexes are chosen to safeguard echoes—fragments of ancient knowledge too valuable to destroy but too dangerous to use. Forbidden to speak lest she accidentally release her echo, codex Delta lives a lonely life. Still, she knows she must obey the wardens’ strict rules to keep her home safe from the vicious beasts, heretical Scrappers, and toxic blood storms that lurk beyond the city walls.
But when Delta breaks her vows to help a young girl escape a blood storm, she begins to have strange dreams, which lead her to question everything she knows to be true about herself and her city. To find answers, Delta must journey to the one place she most fears: the wasteland beyond the walls of Danak-Tol.
Together with her small but feisty mechanical companion Flick, Delta dares the perilous ruins of a long-abandoned skyship, the gullet of a ravenous sphincter worm, and even befriends a young Scrapper named Drii. But all these adventures only lead to more questions. What is the true danger that threatens her entire planet—is it really her echo, or is it the silence that has imprisoned the truth for so long? —Synopsis provided by Atheneum Books for Young Readers
The Delta Codex is a compelling middle-grade sci-fi fantasy that really sticks with you.
The story is told from Delta’s point of view, and her voice is one like any other that I’ve come across. As you learn more about Delta — who she is, who she used to be, and who she can become, you begin to look at the world around you in a different way.
Delta’s story takes place in a rich and complex world brought to life through the deft hands of Deva Fagan. Fagan’s world-building is immersive and the creatures she’s created are truly wonderous.
In her story, Fagan takes readers to a world where knowledge is carefully curated, where certain information is considered dangerous. Its parallels to current trends banning books and limiting free speech make you pause.
The Delta Codex is a multilayered sci-fi novel that moves quickly and sparks thought and imagination.
I read an advanced digital copy of The Delta Codex for review purposes, but liked it so much that I purchased the hard copy for my 12-year-old. She picked it up and wouldn’t put it down. She and I highly recommend it.
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