Brooke finally has the pony that she has always wanted. She and her pony are like two best friends. On a very unusual evening, when the moon is full and unusually big, a mysterious rainbow appears by the light of the moon. Brooke's pony, her brother Dylan's pony, and two others go missing from the stable. There are no signs of a broken gate in the pasture or anyone getting in. There are no clues at all. When Brooke and Dylan finally find out about a magical event that happened that night, it could change all their lives forever!