[5] While Percy Jackson is on a drive with Rachel Dare, he is approached by Charles Beckendorf, and the two head off to attack Luke's ship, The Princess Andromeda.

Kronos, hosted in the mortal body of Luke, is not caught off guard because of a spy at Camp Half-Blood, and Beckendorf is killed in an explosion.

Despite being betrayed by Nico in exchange for information on the boy's mother, Percy is successful and uses his new invulnerability to defeat a small army of Hades's minions.

Even after these setbacks, Percy refuses a chance to surrender offered by Prometheus and entrusts the Titan's gift of Pandora's pithos to Hestia.

Rachel Dare, who has been experiencing inexplicable moments of prophecy, arrives to warn Percy of a drakon that can only be killed by a child of Ares.

The campers do poorly against the drakon until Silena Beauregard arrives disguised as Ares's head counselor Clarisse and breaks the cabin's boycott of the war, getting badly injured in the process.

As Silena lies dying, the campers learn that she was the camp's spy but chose to right her wrongs after her boyfriend Beckendorf's death.

Driven back to the blocks surrounding the Empire State Building, Percy and his friends make their last stand to protect Mount Olympus.

The gods rewards several heroes who were instrumental in defeating the Titans, including Thalia, Grover, Annabeth, Tyson, Clarisse, and Nico.

Privately, Hermes reveals to Percy that Kronos is not dead but is instead hopefully spread so thin that he can never form a consciousness again, let alone a body, as the Titans cannot die any more than the gods can.

While the review notes that the pace sometimes bordered on "frantic," distracting from weaker plot points, the book as a whole remains "clever" and "enjoyably hair-raising.