When the goddess Artemis disappears while hunting a rare, ancient monster, a group of her followers joins Percy and his friends in an attempt to find and rescue her before the winter solstice, when her influence is needed to sway the Olympian Council regarding the war with the Titans.

"The Relentless One, the Bearer of the Bow, the Untamed ... those are only a few of the names Selene DiSilva's answered to over the years. But these days she's content to work in secret, defending the women of Manhattan from the evils of men. She's reclusive, stubborn, and deeply unfriendly to everyone but her dog. But when a woman's mutilated body washes up in Riverside Park wearing a laurel wreath, Selene finds that she can no longer hide in the...

While protecting egotistical transfer student Orion, Artemis makes a mistake that later provides her with the chance that she has both hoped for and dreaded, to prove her courage to herself and others at Mount Olympus Academy.