Riordan, Rick. The Battle of The Labyrinth. New York: Hyperion, 2008.
Of the five books in the Percy Jackson Series, I confess that Book Four, The Battle of the Labyrinth, was by far my least favourite. At precisely the moment when the series should have been rushing headlong toward the climactic ending of Book Five, Riordan's narrative flow gets lost in a sea of reminiscence and some ambitious but sluggish foreshadowing.
Without giving away too much, Riordan's fourth book builds carefully upon the premises already established in the first, second, and third books in the Percy Jackson series. Many of the characters remain the same, although a handful of new ones (both present-day and from past myths) are introduced. Riordan brings in several of these myths most elegantly, and complicates protagonist Percy's life by drawing further parallels between him and some more famous heroes of old. Yet although his allusions are excellent and his references well-placed, Riordan's book struggles to maintain the fast-paced energy of its predecessors: The Battle of the Labyrinth is adequate but not exceptional, and left me somewhat dreading the culminating volume in the series.