Percy starts his freshman year off with a BANG! as always. Cheerleaders that are actually empousai's get him kicked out of yet another school orientation. We then return to Camp Half Blood for a summer of adventure. 
 I feel as though summer middle grade read of choice is Percy Jackson and then during the school year middle grade read is Harry Potter. They're both my obsession lately. 
 It turns out in this book that Luke - son of Hermes and Kronos helper - has been sneaking around the Labyrinth below ground. A giant and dangerous maze which is a short cut to wherever you want to go if you learn to use it to your advantage. Annabeth, Grover, Tyson, and Percy are sent on a quest to find Daedalus (the creator of the maze) before Luke and Kronos do to seek his help. 
 At the same time Nico (view spoiler)[son of Hades (hide spoiler)] from the last novel is on a mission of his own after leaving Camp Half Blood to find his sister no matter what it takes. Even if it means partnering up with some shady characters. 
 (view spoiler)[Kronos - the evil titan god - has put himself inside of Lukes body at the end! Grover finds the great God Pan finally but he was simply waiting to die and to be released from this world. Daedalus sacrifices himself to close the Labyrinth entrance after Kronos's army attacks camp half blood. (hide spoiler)]