When the girls were out of sight, Hans called to the dog. "Come, Chouse.

It's time for us to go now." They got into the boat again and Hans paddled slowly and quietly. But Greta and Anna had reached the turn in the road, so they could not possibly see which way Hans was going.

In the field outside the castle wall, two storks were walking around on their long, slender legs. The girls stopped to watch them.

[Ill.u.s.tration: MR. CHRISTIANSON]

"Oh, Greta, I wish we could get up close to them." Anna ran forward. She thought the storks couldn't possibly see her. But when she was still twenty feet away they lifted their large wings and rose in the air. Soon they had gone over the tops of the trees and high into the sky. Anna watched them until they were out of sight.

"What would you like to see first?" asked Mr. Christianson, when he greeted his two young visitors at the door.

Both girls spoke at the same time. "The little chapel," said Anna. "The library," said Greta.

They visited the chapel first, and then came back to the castle by way of a lovely, shaded path which ran by the side of the moat.

"Hans Christian Andersen used to walk along here, when he visited Vosborg," said Mr. Christianson. "He thought up many of his fairy tales as he strolled along under these trees. In the library there is a volume of his stories that I want to show you. Andersen gave this book to my grandfather, and in the front he has written a little verse about Vosborg."

"Do you suppose we might climb up in the tower?" asked Anna, after they had gone all through the garden and had come back into the inner courtyard. Anna was very fond of climbing.

"Of course you may." Mr. Christianson took them up narrow stairs that kept going up and up and up. Finally they reached the top. From here they could see the ocean in the distance.

"This is almost as high as the tower in our forest," said Greta.

"In olden times this tower was very useful," explained Mr. Christianson.

"From here one could see an enemy when he was still miles away."

"Denmark doesn't have any enemies now, does it?" asked Anna.

"No, Denmark is one of the most peaceful countries in the world. It is almost eighty years since we have been at war with any other nation."

After a while they went down to the library. Mr. Christianson led the girls past rows and rows of books, placed on shelves that reached from the floor to the ceiling. When they came to the farthest corner of the room he stopped and reached for the book of Andersen's Fairy Tales without even looking.

"You see, I know just where it is." Then a worried look came on his face. "Why, I can't understand this," he said. "This book was here last night, for I showed it to some friends. And now it is gone."

"Maybe someone has borrowed it," suggested Greta.

"That is impossible, for I keep the library locked, and none of the servants has the key."

"Maybe you put it back in the wrong place," suggested Anna.

"I'm afraid that is impossible, too. You see I keep this book in a very special place because I prize it more than any other book that I own. I am always careful to put it back in this same spot."

[Ill.u.s.tration: THE COURTYARD OF VOSBORG]

"We'll help you look for it," offered Greta. So the three began searching one shelf of books after another.

"I suppose Hans would say that one of the Nisser had taken it," said Anna jokingly, when they had gone about halfway through the shelves of books.

"I wouldn't be at all surprised if one _had_ taken it," answered Greta quite seriously.

They kept on looking for almost an hour. By this time Mr. Christianson was really worried. He finally called in all the servants and asked if any of them had been in the library that day. None of them had. The disappearance of the book had become a real mystery.

"I should hate to lose this book more than any other book in the library."

"Let's look once more on the shelf where it's supposed to be," said Anna.

Mr. Christianson laughed. "But we looked there very carefully when we first came in."

Anna wanted to look there again, so she ran down the long room to the special shelf.

"Here it is!" she shouted. "Right here on the shelf where it is always kept."

The others rushed up at once. "Well, this _is_ strange," said Mr.

Christianson. "It wasn't here an hour ago, and no one has been in this part of the room since then."

"Except maybe a Nisse," said Greta.

In the front of the book Hans Christian Andersen had written a beautiful poem about Vosborg. It was no wonder that Mr. Christianson treasured this book, for Andersen is the most famous writer of all Denmark.

Children all over the world love his fairy tales.

"It's getting late, Greta, and I think we should--" began Anna and then stopped. A long, low moan cut through the stillness of the room. It seemed to come from quite near.

"What--what was that?" asked Greta.

"Oh, I suppose that was Lady Margaret," explained Mr. Christianson.

"About a hundred years ago she was kept a prisoner in this room for many years, and every now and then we hear her moaning."

"Did you ever see her?" asked Anna.

"Well, no, I never did. But whenever we hear that low moan from this room we know it is Lady Margaret."

"Doesn't it frighten you?" asked Greta.

"Oh, no. We are quite used to it."

"This is really a haunted castle, isn't it?" asked Anna.

"Every castle in Denmark has at least _one_ ghost, Anna."

All the way home the girls talked about the ghost of Lady Margaret. Anna was beginning to think that maybe there really _were_ such things as ghosts and Nisser. When they reached the house, Hans was just getting out of his boat.

"Did you get any fish, Hans?" called Anna.

"No luck today, Anna."

"Are you sure you were trying to catch fish?" asked Greta, in her most teasing manner.

"What do you mean by that, Greta?"