The stone walls were now in ruins. They were overgrown with moss and ivy. But hundreds and hundreds of years ago it was a great stronghold of Ireland's bravest warriors.
The chief of them all was the daring O'Donaghue. Even now he cannot rest easy in his grave. Every seven years he rises up, and, mounting a white horse, rides around Ross Castle. And as he rides every stone goes back into its old place, and the castle is once more as strong and grand as in its best days.
But this is only for the one night. When the sun shines the next morning, a heap of ruins is standing there, where the owls and bats may keep house in comfort.
"How I should like to see the knight on his white horse!" said Norah.
"Yes, but I should be afraid, I'm sure," said Mollie. "After all, the day is the best time to be outdoors, and my bed at home is the safest place after dark."
When the lunch was eaten, the whole party crossed a bridge that spanned the water to Ross Island. The children played games over the smooth lawns, picked flowers, and told fairy stories.
Then Mollie's brother rowed the girls out on the lake. Many a time he rested on his oars while the children called out and then listened for the echo to answer them.
"There it is, hark!" said Tim.
A party of travellers came rowing toward them. They had hired an Irish piper to go with them. As he played a slow tune, the answer came back.
Tim whistled, and the echo repeated it. Then Norah sang the first line of "Come Back to Erin," and the echo sang it back again.