The Queen's Thief Series is a popular fantasy book series written by Megan Whalen Turner. It follows the adventures of a clever thief named Gen, who is known for his cunning and resourcefulness. The series is set in a fictional world inspired by ancient Greece and features themes of politics, loyalty, and deception. The series consists of several novels, starting with The Thief, which introduces Gen and his journey. Each book builds on the previous ones, exploring complex relationships between characters and the intricacies of power. The series is praised for its rich storytelling and well-developed characters.