Statue of Liberty
The Athena Parthenos is the quest item for our other set of heroes: Reyna and Nico. And the difference between this statue and the physician's cure is that Reyna and Nico already have it in their possession at the beginning of the novel. The quest here is to get the stinkin' thing to Camp Half-Blood from halfway across the globe as an act of truce between Romans and Greeks.
Thankfully, Nico can shadow-travel, transporting the statue and his friends with ease. And by "with ease," we mean it costs him his life. But it's still easier than going through security checkpoints at the airport, right? Have you ever tried to check a magical Greek statue?
Reyna often hopes the statue will come to their aid, but it never does. It just…watches stoically. However, during the battle with Orion, Reyna somehow ends up with a magic cloak. A voice in her head tells her it's the aegis of Athena, so maybe the statue was paying attention to all her heroic deeds after all.
Reyna gets the statue to Camp Half-Blood just in time to stop the conflict between Greeks and Romans, but of course Gaea arises as soon as she drops it off, meaning the battle isn't over quite yet…