Library Lost is the sequel to Maya and the Book of Everything and is the second book in the Great Library Series, where two forces, Time and Chaos, battle each other for control of the Great Library, that mysterious place at the center of the universe where all information flows. In the middle of this battle between Time and Chaos is one kid from Earth-Maya Hammond. In Library Lost, Maya is once again on the move, this time with an Apprentice Book named Ariel. Andy, Maya's traveling companion from the 1970s, is now a grown man with a daughter named Viola. He is also in grave danger. Humphrey, a murderous duke from the planet Ilyria, has come to Earth and is after Andy. Maya warns Andy and befriends Viola. When Maya and Viola are threatened by Humphrey, Ariel takes the two girls to Ilyria, where Maya is reunited with Sir John, Simon, Evangeline, and Duke Owen. From there, the action spirals into chaos and destruction. However, Sydda, the Great Library's director, has come up with a daring but dangerous plan-Maya must confront Cinnial, who is allied with Chaos and is the leader of a group of adversarial librarians who want to take over the Great Library. But Maya has grave doubts. How can she ever prevail against someone so powerful? How, indeed?