I've read the first four books in this series to Celyn now and got her #5 for her birthday. 
 A fun read, though the monsters get steadily more outlandish as Rick mines the lesser known corners of Greek myth. In this book we meet the Empousa who are pictured as wearing brazen slippers and bearing flaming hair. The name is said to mean "one-footed." This is because they are a one-legged hybrid, with a donkey's leg and a celestial bronze prosthetic leg... 
 Part of me is wondering how long before South Park's Scuzzlebutt turns up with a hand that's made of celery and Patrick Duffy for a left leg? 
 We also meet Kampe who is depicted as having the head and upper body of a beautiful woman, the lower body of a dragon, a massive scorpion's tail full of venom, snakes around her ankles, and 50 grisly heads of various creatures (wolves, snakes, bears, lions...) bubbling around her waist. She also possesses black wings on her back and a pair of envenomed swords! 
 The labyrinth itself and Daedalus were interestingly portrayed. Percy's girl cluelessness continues unabated. And the Luke/Kronos plot comes to a bubble. 
 I also liked the rather silly Mrs O'Leary hell hound and the issue of giant dog biscuits and squeaky pink full-sized buffalo chew toys. 
 Normally the inconsistent level of farce and semi-seriousness would bug me, but the series' style and charm has somehow inured me to it. 
 Celyn continues to make her 'yes' sign when I ask if I should give these books 5* and who am I to argue with the expert? 
 Percy hits 16 next book - should be fun! 
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