“That’s it,” he said, drawing himself up again.
“What?”
“The basin will empty itself.”
He was right. The water sank very quickly and the bottom of the fountain appeared.
Don Luis stepped into it and squatted on his haunches. The inner wall was lined with a marble mosaic composing a wide red-and-white fretwork pattern. In the middle of one of the frets was a ring, which Don Luis lifted and pulled. All that portion of the wall which formed the pattern yielded to his effort and came down, leaving an opening of about twelve inches by ten.
“That’s where the bags of gold went,” said Don Luis. “It was the second stage. They were despatched in the same manner, on a hook sliding along a wire. Look, here is the wire, in this groove at the top.”
“By Jove!” cried Captain Belval. “But you’ve unraveled this in a masterly fashion! What about the wire? Can’t we follow it?”
“No, but it will serve our purpose if we know where it finishes. I say, captain, go to the end of the garden, by the wall, taking a line at right angles to the house. When you get there, cut off a branch of a tree, rather high up. Oh, I was forgetting! I shall have to go out by the lane. Have you the key of the door? Give it me, please.”
Patrice handed him the key and then went down to the wall beside the quay.
“A little farther to the right,” Don Luis instructed him. “A little more still. That’s better. Now wait.”