I can tell you there are four books in total. The series starts with 'The City of Ember,' followed by 'The People of Sparks,' 'The Prophet of Yonwood,' and 'The Diamond of Darkhold.' Each book builds on the last, creating a rich, post-apocalyptic world that's both thrilling and thought-provoking. I remember binge-reading them all in one weekend because I couldn't put them down. The way Jeanne DuPrau weaves suspense and adventure into the story is just mesmerizing. If you're into dystopian settings with a touch of mystery, this series is a must-read.