21 Days of Fear: One Day, One Letter

By Hervé Commère

An instant New York Times bestseller

A teen is offered the chance to reunite with his missing sister in this heart-wrenching young adult thriller told in a unique format, with chapter-a-day reading perfectly paced for amping up the chilling suspense

What would you do to bring your sister back from the dead?

After Lucas's sister mysteriously disappeared right under his nose ten years ago, his family was torn apart. His mother has been lost in a deep depression, his father unable to speak of what happened, and Lucas trapped in his guilt...until he receives a note that changes everything. He has twenty-one days to find out the truth. Twenty-one days to save his sister...if she really is still alive. Twenty-one days to figure out if he can sacrifice everything to bring her home.

Every action is watched, every choice counted. Can he save his sister without losing himself again?

With this book's unique format, each of the twenty-one chapters is sealed in an envelope which readers can open to reveal the newest twist in Lucas's story.

• Format: Paperback
• Language: English
• ISBN: B0G5ZDLMRN
• ISBN13: 9798347119615
• Release Date: August 2026
• Publisher: Simon & Schuster Books for Young Readers
• Length: 424 Pages
• Weight: 1.60 lbs.
• Dimensions: 1.1" x 5.9" x 8.2"
• Age Range: 14 years and up
• Grade Range: Grade 9 and higher