When a newly orphaned baby in the moon makes friends with the children of Earth, he begins to shine as brightly as possible to ward off their fears.

Fearing that a missing Nightmare King has gone underground to plot revenge, the Guardians enlist the aid of warrior rabbit emissary E. Aster Bunnymund to use his talents and weapons to track down their nemesis.

Provides the background, history, and life of Sanderson Mansnoozie, better known as the Sandman, who helps the Man in the Moon keep children safe at night by bringing them sweet dreams.

When Pitch and Katherine go missing, the Man in the Moon recruits the sleepy but clever Sandman to aid the Guardians' cause in an adventure that finds them struggling to convince their new member to accept a more optimistic perspective.