After they left, Ved created thousands of blood clones, each as tiny as an ant and made from drops of his blood.
He made them undetectable and sent them after the humans, they were going to be his eyes and ears.
Each clone was only slightly stronger than an avarage adult human, if they were discovered they would die instantly.
Then he grabbed Fern and flew off. It took him a few days flying as fast as he could without overtaxing his stamina to reach the boundary of the minor world.
The world barrier opened up and he put Ferb inside and left her for his main body to take care of then left.
He flew back to land and landed on a deep forest, his body merged with the surroundings becoming indistinguishable from the trees and grass.
Then he closed his eyes and saw the world through his blood clones. The humans took a few days but they arrived in some city surrounded by towering walls.
