From New York Times bestselling YA author Rebecca Mix comes the first book in a breathtaking middle grade fantasy duology about a young fairy who has always lived in her heroic grandmother's shadow but now must step up and embark on a quest to save her mother from the ever-creeping mold overtaking their world.

Perfect for readers who loved Brandon Mull's Fablehaven, The City of Ember by Jeanne DuPrau, and Endling: The Last by Katherine Applegate.

The mold takes all.

Twelve-year-old fairy Canary Mossheart knows this better than most. A few years ago, the mold took her papa, and even her famous, former-chosen-one Gran never found a cure. So when Ary's beloved mama falls ill, Ary decides it's taken enough. Armed with only a bucket and a prayer, she sneaks out to find a magical, underground lake whose healing waters are straight out of Gran's adventures.

But when Ary gets there, the lake's bone dry, and instead of healing waters, she finds a terrifying secret: Her entire world is actually trapped inside a giant terrarium--one they were meant to leave centuries ago. Worse, Gran knew and hid the truth, dooming Ary and her generation to a dying, rotting world.

Now, allied with only her doomsday-obsessed frenemy, a timid pill bug, and a particularly grumpy newt, Ary has one week to unravel the clues and find a way out of the terrarium--or they'll be trapped for good. .

Author: Rebecca Mix
Binding Type: Hardcover
Publisher: HarperCollins
Published: 09/05/2023
Pages: 432
Weight: 0.98lbs
Size: 8.54h x 5.87w x 1.25d
ISBN: 9780063254053
Audience: Ages 9-12

Accelerated Reader:
Reading Level: 5.4
Point Value: 14
Interest Level: Middle Grade
Quiz #/Name: 522102 / Mossheart's Promise


Review Citation(s):
Kirkus Reviews 07/15/2023
Publishers Weekly 07/24/2023
School Library Journal 11/01/2023 pg. 58