Percy Jackson and the Olympians: Battle of the Labyrinth features the fourth of Percy's quests since he found out that he was a demigod and the son of the Greek god Poseidon three years ago. If you haven't read the first 3 books of the series (The Lightning Thief, The Sea of Monsters, and The Titan's Curse), I would highly recommend that you do so first.
Percy's fourth summer at Camp Half-Blood starts off with news of the war between the Greek gods and the Titans drawing closer. The ancient Titan Kronos is awakening, and his army is getting ready to launch a full-scale invasion on Camp-Half Blood. In a desperate attempt to prevent this, Annabeth Chase leads a small group of demigods (including Percy) into the mysterious and ever-changing Labyrinth itself from the legends of Greek mythology on a quest to find its infamous inventor, and they soon come to find out the dark and unexpected role it plays in Kronos' plan.
I absolutely loved this book--in fact, I think it's my favorite of all the five books in the series! Unlike the other books of the series, The Battle of the Labyrinth had a darker and more complex plot, filled with tension and suspense as the demigods slowly made their way through the twists and turns of Labyrinth--you never knew what they were going to face next. I also enjoyed the subtle hints scattered throughout the book of the relationship between Percy and Annabeth changing--with Percy grappling with his emerging feelings for Annabeth--definitely foreshadowing for the next book of the series.
Overall, this book was a thriller, and I was completely hooked from beginning to end. I would give this book an unwavering five stars. A must-read for anyone who thoroughly enjoyed the first three books of the Percy Jackson series.