Oz is knotted with social unrest: The Emerald City is mounting an invasion of Munchkinland, Glinda is under house arrest, the Cowardly Lion is on the run from the law, and Dorothy is back. Amid chaos and war, Elphaba’s green granddaughter born at the end of ‘Son of a Witch’, comes of age. Rain will take up her broom, and bring the series to a close.