What do you do after you get all 5 Sacred items on Mythology Island?

Take the five sacred items to the Tree of Immortality, where Athena will show you how to read the secret message written on the items.

(It reads "Whoever wields/ the five sacred / objects will rule/ all of / Poptropica".)

Zeus will appear and steal the sacred items. Athena will suggest you make another plea to Hercules for his help.