It's about an adventure of Persy Jackson,Son of Posiden,god of seas. Persy goes on an adventure with his two friends,Annabeth and Tyson,Tyson is a cyclopse, who turns out to be persy's brother, They are on this quest, to save their camphalfblood that has been played by darkness and a tree named Thalia who once was a girl that has been poisoned by an evil person named Luke son of Hermies. Persy, Annabeth,and Tyson have to get a fleece that will heel the sickness and repels evil. In order to do that they have to defeat an evil cyclopse. After they defeated the cyclopse and brought back the fleece,everyone was suprised and happy about it. Once agian persy was a hero and the camp halfblood was saved ,Thalia"s tree was healed ...it even brought Thalia back to human form.