The realm of Possibility is real. Adalay Bancroft is one of the few children who are talented enough to be invited for a visit. But it's not for fun. Mr. Wixlby needs her powerful imagination to save his realm.

Time and again children have entered Possibility to rid the realm of a mysterious villain who once more plagues the land. This persistent foe tries everything in her power to prevent imagination and terrorize the Wetalwil who live there. Only when Adalay learns to fully wield her imagination does she stand a chance of banishing this enemy. With Mr. Wixlby's guidance and a splash of determination, she begins to understand just how limitless her own imagination really is.

As Adalay unravels this mystery, clues point to another way to save Possibility. If Adalay is willing to risk everything, she may be able to free the realm and end the attacks for good.