Return To Ursalia (S05E12)

Sir Thornberry sends a message that draws both the Gummis and Igthorn back to Ursalia, where a group known as the Barbics has made their home. Unfortunately, these new inhabitants are quite unfriendly and harbor a strong animosity towards humans. Their goal is to find a powerful weapon hidden in Ursalia to take revenge on humanity. Coincidentally, this very weapon is on the verge of being seized by Igthorn.