and sit down before Merlin, who cried to them--

"Because ye know not what it is that hinders the foundation of the castle,
ye have advised my blood for a cement to it, as if that would avail; but
tell me now rather what there is below that ground, for something there is
surely underneath that will not suffer the tower to stand?"

The wizards at these words began to fear, and made no answer. Then said
Merlin to the king--

"I pray, Lord, that workmen may be ordered to dig deep down into the
ground till they shall come to a great pool of water."

This then was done, and the pool discovered far beneath the surface of the
ground.

Then, turning again to the magicians, Merlin said, "Tell me now, false
sycophants, what there is underneath that pool?"--but they were silent.
Then said he to the king, "Command this pool to be drained, and at the
bottom shall be found two dragons, great and huge, which now are sleeping,
but which at night awake and fight and tear each other. At their great
struggle all the ground shakes and trembles, and so casts down thy towers,
which, therefore, never yet could find secure foundations."

The king was amazed at these words, but commanded the pool to be forthwith
drained; and surely at the bottom of it did they presently discover the
two dragons, fast asleep, as Merlin had declared.

But Vortigern sat upon the brink of the pool till night to see what else
would happen.