"Folk of the Air" is a young adult fantasy trilogy written by Holly Black. The series follows the story of Jude Duarte, a mortal girl living in the treacherous world of Faerie, where she navigates political intrigue and power struggles among the Fae. The trilogy includes three books: "The Cruel Prince," "The Wicked King," and "The Queen of Nothing." It explores themes of ambition, betrayal, and identity, as Jude seeks to gain power and respect in a realm that despises humans. The series has received critical acclaim for its rich world-building and complex characters.