I only read this book because I wanted to finish the Percy Jackson series even though I didn't like it very much. Out of all the books in the series, I thought this one was the most creative. The idea of a big maze underground was pretty cool, and I liked that they included the mortal girl in the end as the key to getting through the maze. There was a lot of mystery in this book, because not every body was how they seemed and there were some characters that seemed unimportant but, in the end, they were key parts in the resolution of the story. In this particular addition to the series, Percy has to go on another quest (you guessed it) but this time he is not leading it, Annabeth is. They have to go into the underground labyrinth to try and stop Luke from finding a way to navigate it, and the crew faces many obstacles along the way. They meet many different creatures, find unexpected challenges, fight monsters, and are surprised to learn that characters you would have least expected to be important rise to the occasion and save the not-so-perfect half-bloods. Even though the Percy Jackson series did not live up to what I expected it to be, the fourth book was so far the best because it had deeper meanings behind the generic plot line that so many books are based off of. This book would be a good read for elementary to middle schoolers who enjoy fantasy.