The Nameless Spirit informs you that only through the use of a magic scroll can the force field be dispersed. He then informs you that is was created by his "double." Keep listening to the story.
The Nameless Spirit says he needs a special parchment to create the scroll that will release the magic force field. Go to the Wall of Argos and defeat the Canyon Antelope to bring back its skin.
Monsters to Hunt: Canyon Antelope, Canyon Antelope Slave