For five years, Shannon Jackson has reigned as the undisputed "Queen of Camp Half-Blood." As the first forbidden child of Poseidon, she embraced her role as a solitary legend, earning the camp’s worship through lethal skill and cold authority. But when her twelve-year-old brother, Percy, arrives and is claimed in a blaze of divine glory, Shannon’s world is upended. Relegated from the "Chosen One" to a mere older sister, Shannon must navigate a dangerous cocktail of fierce protectiveness and venomous jealousy. As the Great Prophecy looms, she must decide if she will be Percy’s greatest shield—or his most dangerous rival.