The New York Times bestselling author of The Unwanteds brings us an epic animal adventure story perfect for fans of Pax and A Wolf Called Wander.

Clarice is a young ship mouse grieving the loss of her mother when a mutiny forces her onto a small, leaky boat with a dangerous cat. Worse, she is separated from her younger brother, Charles Sebastian, who is trapped aboard the great ship.

Clarice and Charles Sebastian were taught to always be careful-but they will need to grow bold if they are to survive . . . and find one another again.