'I think it's out of a book about Mexico or Peru or Ingots or some geographical place,' said Lucy; 'it had a green-and-gold binding. I think you used it for the other end of the outer justice court. And if you did, this dome's solid silver, and there's a hole in it, and under this dome there's untold treasure in gold incas.' 'What's incas?' 'Gold bars, I believe,' said Lucy; 'and Mexicans come down through the hole in the roof and get it, and when enemies come they flood it with water. It's flooded now,' she added unnecessarily. 'I wish adventures had never been invented,' said Brenda. 'No, dear Lucy, I am not whining. Far from it. But if a dear little dog might suggest it, we should all be better in a home, should we not?' All eyes now perceived a dark hole in the roof, a round hole exactly in the middle of the shining dome. And as they gazed the dark hole became light. And they saw above them a white shining disk like a very large and very bright moon. It was the light of day. 'Some one has opened the trap-door,' said Lucy. 'The Ingots always closed their treasure-vaults with trap-doors.' The bright disk was obscured; confused shapes broke its shining roundness. Then another disk, small and very black appeared in the middle of it; the black disk grew larger and larger and larger. It was coming down to them. Slowly and steadily it came; now it reached the level of the dome, now it hung below it; down, down, down it came, past the level of their eager eyes and splashed in the water close by the ship. It was a large empty bucket. The rope which held it was jerked from above; the bucket dipped and filled and was drawn up again slowly and steadily till it disappeared in the hole in the roof. 'Quick,' said the parrot, 'get the ship exactly under the hole, and next time the bucket comes down you can go up in it.' 'This is out of the _Arabian Nights_, I think,' said Lucy, when the yacht was directly under the hole in the roof. 'But who is it that keeps on opening the books? Somebody must be pulling Polistopolis down.' 'The Pretenderette, I shouldn't wonder,' said Philip gloomily. 'She isn't the Deliverer, so she must be the Destroyer. Nobody else can get into Polistarchia, you know.' 'There's me.' 'Oh, you're Deliverer too.' 'Thank you,' said Lucy gratefully. 'But there's Helen.' 'She was only on the Island, you know; she couldn't come to Polistarchia. Look out!' The bucket was descending again, and instead of splashing in the water it bumped on the deck. 'You go first,' said Philip to Lucy. 'And you,' said Max to Brenda. 'Oh, I'll go first if you like,' said Philip. 'Yes,' said Max, 'I'll go first if you like, Brenda.'