Grana used to tell the best stories, and Mable used to long to soar through the heavens. Nowadays, Grana mostly lies in bed and Mable stays close to home. But one day, Grana asks, “If we can touch the moon, then what is impossible?” So Mable decides to do just that, embarking on a journey through the stars where The Seven Sistahs, The Big Dipper, and other constellations help her on her quest and teach her about African mythology and African American history. With the support of her new companions, Mable reaches for her biggest dream yet: to make her sick grandma well again.