Codebreaker - by Jay Martel (Paperback)

About the Book

Seventeen-year-old Mia Hayes' world shatters when her mother is killed and her father disappears, leaving behind a coded message that sends her and a rebellious hacker on a high-stakes race through D.C. to uncover government secrets and stop a devastating attack.

Book Synopsis

This original, interactive thriller from debut author Jay Martel follows a brilliant teenage girl as she races across D.C. to decode the clues her father left behind, which may just be the key to saving the country from a devastating tragedy.

Mia Hayes has peaceful plans for the summer--find a part-time job at a coffee shop and work on her college applications. Those plans are shattered one night when government agents arrive unannounced at her home seeking something they believe her father has taken. When the dust settles, her mother is dead and her father is gone, a fugitive on the run.

Three weeks later, and still reeling from her father's betrayal, Mia spends her seventeenth birthday at a protest in the heart of D.C., where she meets Logan, a rebellious and charming hacker. Just as she's enjoying her first happy moment since the night her world exploded, a voicemail from her father arrives to upend everything she believed about her family, her past, and what really happened that night three weeks ago. Even more, the voicemail hides another encoded message inside which, once Mia solves it, sets her and Logan off on a mission from her sleepy suburb straight into the heart of the federal government.

With the same agents now hot on their trail, Mia and Logan must navigate their way through American history's most iconic sites and uncover its most well-hidden secrets to reveal the truth about her family and stop a deadly attack.

In this non-stop thrill ride, the reader has the chance to test their own codebreaking skills alongside Mia, lending an exciting interactive element to this page-turning thriller packed with action, romance, and life-changing revelations.

Review Quotes

Nominated for the Best Young Adult of 2026 at the Edgars Awards

One of PW's "New and Noteworthy Children's and YA Books: July 2025"
One of WAMC's "Roundtable" Picks
One of Bookstr's "New in Young Adult: Fiction Books Releasing This July"
One of Beyond the Bookends's "July 2025 Book Releases"
One of Perfect Duluth Day's "Duluth Book Releases in 2025"
One of Thrift Book's "July Books We're Excited About"

"Clever codes, puzzles, and ciphers form the base of this intricately designed codebreaker mystery that's enlivened by page-turning action and Mia and Logan's sharp banter and magnetic chemistry. A beginning author's note instructs readers on how to participate in the codebreaking and investigating alongside Mia, injecting a playful interactive element to Martel's propulsive debut novel."--Publishers Weekly (Starred Review)

"The propulsive plot is peppered with their clever banter, which balances the weightier themes of social justice and Mia's sympathetic struggle with disillusionment as she suddenly makes disorienting discoveries . . . A smart, gripping thriller with engaging interactive elements."--Kirkus Reviews

"If The Da Vinci Code had a YA cousin, it would be Codebreaker . . . With a lot of heart, especially regarding how Mia's grief manifests itself, this propulsive novel will appeal to fans of puzzles and spy stories."--Booklist

"Author team Andy Bennett and Katy Helbacka debut under the Martel pen name with an exciting adventure that is a blend of National Treasure and The Inheritance Games . . . This uniquely engaging thriller features an interactive format . . . [and] is an engrossing, adrenaline-packed mystery. Recommended for fans of Jennifer Lynn Barnes, Holly Jackson, and Kayvion Lewis."--School Library Journal

"This Duluth writing couple have real talent . . . [Codebreaker's] breakneck pace will attract readers of all ages."--The Minnesota Star Tribune

"A true original here . . . 'National Treasure' energy with the pulse of modern YA. Perfect for teens (and adults) who like their fiction fast, clever and immersive."--Charleston Post and Courier

"Codebreaker is an exciting interactive adventure filled with spies, codes, twists, and romance. You'll love working alongside Mia to solve puzzles, decode ciphers, uncover buried secrets, and work to save the country in this innovative thriller from Jay Martel. I know I did."--G. T. Karber, internationally bestselling author of the Murdle series

"The Da Vinci Code for Gen Z. Teen mystery (and history!) fans will devour this. Once I started reading, I couldn't stop!"--Alexa Donne, author of The Ivies and The Bitter End

"At once an action-packed political thriller, captivating puzzle game, and heartfelt love story, Codebreaker is a delight from start to finish! Perfect for fans of National Treasure, this whip-smart, original debut will have readers tearing through the pages as they race alongside Mia to find answers."--Olivia Worley, author of People to Follow

"A fast-paced, ingenious, and twisty caper, Codebreaker is a roller-coaster ride with a heart of gold. Fans of The Inheritance Games are in for a treat."--Ripley Jones, author of Missing Clarissa

"Codebreaker is a touching and witty coming of age story disguised as an action-packed suspense novel. You'll be looking for secret codes long after you finish the last page."--Kate McLaughlin, author of Pieces of Me

About the Author

JAY MARTEL is the pen name of husband-and-wife writing team Andy Bennett and Katy Helbacka. They've spent the past twenty years collaborating on everything from theatrical productions to escape rooms to their son, Theo. Andy works in cybersecurity and has an MFA in creative writing from NYU and Katy is an award-winning theatrical producer, writer, actor, and director. They live in northern Minnesota. Codebreaker is their debut novel.