"We intend to stop on our way at the Flatheads' Enchanted Mountain and punish the Su-dic for his misdeeds." That satisfied Aurex and when Ozma and her followers trooped over the bridge to the shore, having taken leave of their friends, all the Skeezers cheered them and waved their hats and handkerchiefs, and the band played and the departure was indeed a ceremony long to be remembered.
The three Adepts at Magic, who had formerly ruled the Flatheads wisely and considerately, went with Princess Ozma and her people, for they had promised Ozma to stay on the mountain and again see that the laws were enforced.
Glinda had been told all about the curious Flatheads and she had consulted with the Wizard and formed a plan to render them more intelligent and agreeable.
When the party reached the mountain Ozma and Dorothy showed them how to pass around the invisible wall--which had been built by the Flatheads after the Adepts were transformed--and how to gain the up-and-down stairway that led to the mountain top.
The Su-dic had watched the approach of the party from the edge of the mountain and was frightened when he saw that the three Adepts had recovered their natural forms and were coming back to their former home.

He realized that his power would soon be gone and yet he determined to fight to the last.

He called all the Flatheads together and armed them, and told them to arrest all who came up the stairway and hurl them over the edge of the mountain to the plain below.

But although they feared the Supreme Dictator, who had threatened to punish them if they did not obey his commands, as soon as they saw the three Adepts they threw down their arms and begged their former rulers to protect them.
The three Adepts assured the excited Flatheads that they had nothing to fear.
Seeing that his people had rebelled the Su-dic ran away and tried to hide, but the Adepts found him and had him cast into a prison, all his cans of brains being taken away from him.
After this easy conquest of the Su-dic, Glinda told the Adepts of her plan, which had already been approved by Ozma of Oz, and they joyfully agreed to it.

So, during the next few days, the great Sorceress transformed, in a way, every Flathead on the mountain.
Taking them one at a time, she had the can of brains that belonged to each one opened and the contents spread on the flat head, after which, by means of her arts of sorcery, she caused the head to grow over the brains--in the manner most people wear them--and they were thus rendered as intelligent and good looking as any of the other inhabitants of the Land of Oz.
When all had been treated in this manner there were no more Flatheads at all, and the Adepts decided to name their people Mountaineers.