After you gather all the starstones and put them in place in Antarctica, you begin Chapter 4: Resurrection of the Hero.
A long cut scene will take place. Afterward, go up to the door and talk to Elle. After another cut scene, go down and talk to the Elle from the surface. After another cut scene, touch the box to get the Hero Pike and Hero Armor. Equip them and leave. Exit the house and there will be a cut scene.
Now leave town. There are monsters near where you exit. You can use the Bone Pin to quickly warp to the entrance. If you want to go through the forest instead, go south, then east to the next area. Go north from there. Then go east and you will reach a dark area. Go southeast and you will reach "Bridge". Unfortunately, the bridge is broken so you will have to take the long way out of here. Go east, then north to another dark area. Go clockwise and then use the southeast exit (not the one with rocks around it). Go south, then follow the path around to the next area, where there are worms coming out of the tree trunks. Go southwest, then make your way to the northwest exit. Go west to the next area and then south from the bridge. Go south, then west, then south a couple of times. Then you can go south to get out of the forest.
From Norfest, walk around until you find a dock where you can get in your ship. Then sail to Freedom and use the air strip there to fly to Mosque. From there, walk east to Siberia. Go as far east as you can to reach the Lab Tower.