ISBN-13: 9780141346137 / Angielski / Miękka / 2013 / 304 str.
ISBN-13: 9780141346137 / Angielski / Miękka / 2013 / 304 str.
Percy Jackson - the son of Poseidon - has had an unnervingly quiet school year. But then he discovers that the magical borders protecting Half Blood Hill, a summer camp dedicated to training young demi-gods, are failing. Unless something is done, the camp will be attacked by demons and monsters.