The long-awaited prophecy surrounding Percy Jackson's sixteenth birthday unfolds as he leads an army of young demigods to stop Kronos in his advance on New York City, while the Olympians struggle to contain the rampaging monster, Typhon.

When the goddess Artemis goes missing, she is believed to have been kidnapped. And now it's up to Percy and his friends to find out what happened. Who is powerful enough to kidnap a goddess? They must find Artemis before the winter solstice, when her influence on the Olympian Council could swing an important vote on the war with the titans. Not only that, but first Percy will have to solve the mystery of a rare monster that Artemis was hunting when...