"The Thea Sisters are in Brazil for the summer Mouselympics! They've been invited to watch their friend Beatrice and her team train for the big race. Strange things start to happen during practices. The team's sneakers get stolen, their batons go missing, and the team members start to lose patience with one another. Can the Thea Sisters help figure out what's causing all the trouble before it's too late?"--Back cover.

The Seven Roses, magical flowers which bloom forever and which are linked to the health of the Land of Flowers, are dying, and the Thea sisters together with Will Mystery must travel to that land to discover the reason--a journey where every flower seems determined to hinder their passage.

There is a crisis in the Starlight Kingdom, one of the fantasy worlds: its stars, powered by a special kind of stardust, are fading and may soon go out forever, leaving the Kingdom in darkness--so the Thea sisters and Will Mystery set out for Brightstar Castle to discover what is wrong, but first they must overcome the obstacles and challenges that the fairies are placing in their way.

The Thea Sisters are summoned to the Seven Roses Unit by Will Mystery, but when they get there Will is missing; the sisters follow a trail of clues to the Fantasy Kingdoms, and find out that the Mayhem Mirror has been disturbed, and a terrible curse is about to be unleashed on the Fantasy Kingdoms, and it will be up to them to find the eight Harmonies which can break the curse and save the Kingdoms.