The Quest to Return the Athena Parthenos was a quest undertaken by Reyna Avila Ramírez-Arellano, Gleeson Hedge, and Nico di Angelo. It was to transport the Athena Parthenos statue from Epirus, Greece to Half-Blood Hill in front of Camp Half-Blood. Shadow travel was used to transport the statue as well as Reyna's ability to push the abilities of others further than they would normally go. The significance of a Roman praetor being the one to return the statue was that it showed an attempt to heal the rift between the two cultures by having a Roman return a precious Greek artifact that was stolen.
After Nico and the Seven shadow travel out of the House of Hades, they meet up with Reyna and discuss what to do next. It is decided that the Seven will go to Athens while Nico, Reyna and Coach Hedge will take the Athena Parthenos to Camp Half-Blood to prevent the looming war between the Greeks and the Romans.
Reyna, Nico, and Coach Hedge manage to get the Athena Parthenos to Camp Half-Blood, and set it down by Thalia's pine tree, thereby healing the ancient breach between Greek and Roman demigods at last, and allowing the gods to come to the aid of the Seven in Athens.