An instant #1 New York Times bestseller!

Award-winning actress Elizabeth Olsen and esteemed musician Robbie Arnett have created a fresh approach to wellness in a new series that shows children ways to manage anxiety. A perfect back-to-school read!

Meet Hattie Harmony, Worry Detective.

She’s always there to help her friends when they need her. And the first day of school can cause a lot of jitters—from speaking in front of the class to taking the bus. Hattie always finds the perfect tools to calm her friends’ bodies and minds. But when her own fears start to bubble up, can Hattie learn to overcome them herself?

Critically acclaimed actress Elizabeth Olsen and esteemed musician and writer Robbie Arnett have created an irresistible new character filled with warmth and humor to introduce the youngest readers to the importance of self-care.