The film tells the story of Mosley, a "thoriphant" who rebels against his life of servitude and embarks on a treacherous journey to find the fabled city of Uprights.

When teenagers Rachel and Grace travel inside a super-powered rainbow to China, they disturb nature's balance. Using Rachel's connection to the energy of the rainbow and with help from their new friend Xiao Cheng, they must race against time to save the Earth.