When night fell all the interior of the Great Dome, streets and houses, became lighted with brilliant incandescent lamps, which rendered it bright as day. Dorothy thought the island must look beautiful by night from the outer shore of the lake. There was revelry and feasting in the Queen's palace, and the music of the royal band could be plainly heard in Lady Aurex's house, where Ozma and Dorothy remained with their hostess and keeper. They were prisoners, but treated with much consideration.  
Lady Aurex gave them a nice supper and when they wished to retire showed them to a pretty room with comfortable beds and wished them a good night and pleasant dreams.
 
"What do you think of all this, Ozma?" Dorothy anxiously inquired when they were alone.
 
"I am glad we came," was the reply, "for although there may be mischief done to-morrow, it was necessary I should know about these people, whose leaders are wild and lawless and oppress their subjects with injustice and cruelties. My task, therefore, is to liberate the Skeezers and the Flatheads and secure for them freedom and happiness. I have no doubt I can accomplish this in time."
 
"Just now, though, we're in a bad fix," asserted Dorothy. "If Queen Coo-ee-oh conquers to-morrow, she won't be nice to us, and if the Su-dic conquers, he'll be worse."
 
"Do not worry, dear," said Ozma, "I do not think we are in danger, whatever happens, and the result of our adventure is sure to be good."
 
Dorothy was not worrying, especially. She had confidence in her friend, the fairy Princess of Oz, and she enjoyed the excitement of the events in which she was taking part. So she crept into bed and fell asleep as easily as if she had been in her own cosy room in Ozma's palace.
 
A sort of grating, grinding sound awakened her. The whole island seemed to tremble and sway, as it might do in an earthquake. Dorothy sat up in bed, rubbing her eyes to get the sleep out of them, and then found it was daybreak.
 
Ozma was hurriedly dressing herself.
 
"What is it?" asked Dorothy, jumping out of bed.
 
"I'm not sure," answered Ozma "but it feels as if the island is sinking."
 
As soon as possible they finished dressing, while the creaking and swaying continued. Then they rushed into the living room of the house and found Lady Aurex, fully dressed, awaiting them.
 
"Do not be alarmed," said their hostess. "Coo-ee-oh has decided to submerge the island, that is all. But it proves the Flatheads are coming to attack us."
 
"What do you mean by sub-sub-merging the island?" asked Dorothy.
 
"Come here and see," was the reply.
 
Lady Aurex led them to a window which faced the side of the great dome which covered all the village, and they could see that the island was indeed sinking, for the water of the lake was already half way up the side of the dome. Through the glass could be seen swimming fishes, and tall stalks of swaying seaweeds, for the water was clear as crystal and through it they could distinguish even the farther shore of the lake.
 
"The Flatheads are not here yet," said Lady Aurex. "They will come soon, but not until all of this dome is under the surface of the water."
 
"Won't the dome leak?" Dorothy inquired anxiously.
 
"No, indeed."
 
"Was the island ever sub-sub-sunk before?"
 
"Oh, yes; on several occasions. But Coo-ee-oh doesn't care to do that often, for it requires a lot of hard work to operate the machinery. The dome was built so that the island could disappear. I think," she continued, "that our Queen fears the Flathea............