Julian was astonished. It was obvious that nobody could possibly climb up the tower from the inside! Then how in the world could there have been a face at the tower window? He began to feel rather uncomfortable. Was it a real face? If not what could it have been?

“This is queer,” said Dick, thinking the same as Julian, and pointing to the heaped-up stones on the ground floor of the tower. “It does look absolutely impossible for anyone to get up into the top of the tower. Well — what about that face then?”

“Let’s go and ask that old woman if there is any way at all of getting up into the tower,” said Julian. “She might know.”

So they left the castle, walked across the courtyard, back to the little tower in the outer wall that guarded the big gateway. The old woman was sitting by the turnstile, knitting.

“Could you tell us, please, if there is any way of getting up into the tower over there?” asked Julian.

The old woman answered something, but it was difficult to understand a word she said. However, as she shook her head vigorously, it was plain that there was no way up to the tower. It was very puzzling.

“Is there a better plan of the castle than this?” asked Julian, showing his guide-book. “A plan of the dungeons, for instance — and a plan of the towers as they once were, before they were ruined?”

The old lady said something that sounded like “Society of Reservation of something-or-other.”

“What did you say?” asked Julian, patiently.

The witch-like woman was evidently getting tired of these questions. She opened a big book that showed the amount of people and fees paid, and looked down it. She put her finger on something written there, and showed it to Julian.

“Society for Preservation of Old Buildings,” he read. “Oh — did somebody come from them lately? Would they know more than it says in the guide-book?”

“Yes,” said the old woman. “Two men came. They spent all day here — last Thursday. You ask that Society what you want to know — not me. I only take the money.”

She sounded quite intelligible all of a sudden. Then she relapsed into mumbles again, and no one could understand a word.

“Anyway, she’s told us what we want to know,” said Julian. “We’ll telephone the Society and ask them if they can tell us any more about the castle. There may be secret passages and things not shown in the guide-book at all.”

“How exciting!” said George, thrilled. “I say, let’s go back to that tower and look at the outside of it. It might be climbable there.”

They went back to see — but it wasn’t climbable. Although the stones it was built of were uneven enough to form slight foot-holds and hand-holds it would be much too dangerous for anyone to try to climb up — even the cat-footed Jo. For one thing it would not be possible to tell which stones were loose and crumbling until the climber caught hold — and then down he would go!