"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 Flatheads will attack the island and try to break the glass of the dome."