Nancy Drew sank down upon the davenport and studied the note which had just been delivered at her door. The message was brief, but its words carried an import of veiled violence which mystified and frightened her. It read:

“Be warned in time. Keep away from the Turnbull house.”

The threatening communication was unsigned but was written in a bold scrawl, and, Nancy fancied, was unmistakably the handwriting of a man.

“Who could have sent it?” she asked herself, in amazement. “Why, I’ve taken special pains not to let anyone know I am going to the Turnbull house. Even Hannah doesn’t know I am to visit there.”

How could anyone have learned of her plans? Nancy Drew turned this question over in her mind as she sat propped up with pillows in a corner of the big davenport, the very picture of a pretty girl in a brown study over some knotty problem. The more she thought about it, the knottier her problem became, for she had communicated with Rosemary and Floretta by writing, and unless her note to them had been intercepted in the mail, there was no way, to her knowledge, that the information could have become known to a third person.

“I’m almost tempted to believe in ghosts myself,” she thought. “It’s positively uncanny!” She reflected a moment and then chuckled: “But, anyway, I don’t believe the ghost is a very brave one, or he wouldn’t be afraid to have me on his trail.”

As she considered the possibility of danger connected with her visit to the old mansion, the smile faded from her face and all facetious thoughts about ghosts passed from her mind. The note had frightened her, but it had not deterred her in her purpose to do all within her power to solve the mystery surrounding The Mansion. Nancy possessed the fighting instincts of her father, and it would take more than a threat to keep her away from the Turnbull house. She was convinced that underhand work was going on at The Mansion and she was determined to expose it if it were possible to do so.

“I think Dad was wise to suggest that I take his revolver,” she told herself. “And I’ll take plenty of ammunition, too! Enough to annihilate an army! Though, truth to tell, I don’t know whether I could hit the broad side of a barn or not.”

Getting up from the davenport, Nancy crossed over to the desk, and with a glance at the window shades to see that they were down, removed the revolver from the drawer. Taking it upstairs, she placed it carefully in her traveling bag. As she started back down the stairs, she heard a light step on the porch.

She paused and listened.

“I wonder if I’m to get another note?” flashed through her mind.

Before she could move forward, the door opened and Hannah Gruen came in.

“Oh, it’s you,” Nancy murmured in relief.

“Why, yes. Who did you think it was?”

“Well, I didn’t know,” and Nancy smiled. “I wouldn’t have been much surprised if a ghost had walked in.”

“A ghost?” Hannah asked in alarm. “What do you mean?”

“Oh, nothing,” Nancy assured her hastily. “I was only joking.”

Before the housekeeper could question her further, the girl said good night and retreated to her bedroom.

“I’ll not let that anonymous note disturb my sleep,” she told herself resolutely, as she tumbled into bed, “and tomorrow I’ll start for The Mansion just as I planned.”

After she had finished her breakfast the next morning, Nancy Drew took leave of the housekeeper, and, closing up the house, started off for Cliffwood in her roadster.

There was not a sign of life about the old stone house as she drove up, and she began to wonder if anything had happened to Rosemary and Floretta since her last visit.

However, before she could lift the knocker on the front door, Rosemary greeted her.

“I saw you coming up the drive. Oh, you don’t know how glad we are that you have come!” she declared cordially. “You see, we were afraid you might change your mind. We couldn’t have blamed you if you had.”

“I hope nothing has happened since I was here the other day,” Nancy said quickly.

“Oh, it’s been almost unbearable. We had made up our minds to leave the place if you didn’t come today.”

Rosemary’s face was strained, and Nancy thought she looked as though she had not slept for several nights. The ordeal of remaining in the house was gradually wearing her down.

“Last night we heard music again,” she said, in a very low tone.

“What sort of music?”

“It seemed to come from a stringed instrument. It might have been a guitar.”

“From what part of the house?”

“That was the strange part of it. The sound wasn’t localized. It seemed to move from one part of the house to another.”

“Did you hear the music distinctly?”

“No; the sound was muffled, as though it were a long way off. Oh, it was almost ghostly!” Rosemary shuddered and turned appealing eyes upon Nancy. “Tell me, do you believe in the supernatural?”

“I am almost certain your house is not haunted,” Nancy returned firmly, for she saw that Rosemary’s iron nerve was beginning to go back on her. “How long did the music last?”

“About half an hour, I should judge.”

“Did Miss Floretta hear it, too?”

“Oh, yes. She’s positively ill this morning. She didn’t get out of bed. We’ll go to her room now if you like.”

“Perhaps it would be better not to disturb her.”

“Oh, she wanted to see you just as soon as you arrived.”

Rosemary led the way through the long, dark corridor and to the stairway.

“I’ll show you to your room first and then you can talk with Floretta,” she told Nancy when they reached the upper hall.

Rosemary opened a door and permitted Nancy to enter ahead of her. The bedroom was a large, comfortable one with an old-fashioned canopy bed and heavy mahogany furniture.

“I have assigned you the room right next my own,” Rosemary explained. “If anything should happen during the night you could rap on the wall or cry out and I would hear you.”

Nancy nodded soberly.

“And the key is in the door,” Rosemary continued. “Floretta and I always lock our doors.”

“I will lock mine too,” Nancy promised.

“Are you certain you want to go through with it?” Rosemary questioned anxiously. “If anything should happen to you I’d never forgive myself.”

“I don’t believe anything serious will happen.”

“I wish I could feel as confident,” Rosemary sighed. “Shall we go to Floretta now?”

“Yes, I am ready. I will unpack my bag later.”

Nancy followed Rosemary down the hall and they entered the bedroom in the east wing.

“Welcome to the haunted house,” Floretta murmured as a greeting to the girl. She was propped up in bed with cushions and her face was white and haggard. A tray on a table near the bed had been left practically untouched.

“Floretta, you didn’t eat your breakfast,” Rosemary chided gently.

“Oh, I couldn’t, Rosemary. I’m so upset. I can’t stay in this horrible place much longer.”

“Miss Drew is here to help us,” Rosemary responded quietly.

“But can she? I’m beginning to doubt that anyone can help us!”

“Nonsense! You mustn’t let your nerves get the best of you!”

“I think I can help you.” Nancy smiled reassuringly. “At least I will do my best. I intend to go all over the house and see if I can locate secret panels or trapdoors.”

“I don’t believe it will do any good,” Floretta declared pessimistically. “I never heard of anything like that in the house.”

“I may as well have a look, anyway,” Nancy said easily. She remembered something which she intended to ask the Turnbull sisters. “Tell me, did you mention to anyone that I was coming here for a visit?”

“No,” Rosemary answered promptly. “We took care not to mention it to a soul.”

“Of course we talked about your note when it came,” Floretta added. “But we didn’t let out a hint of its contents to anyone. Why do you ask?”

Nancy hesitated, then deciding that it could do no particular harm to tell the Turnbull sisters of the note she had received, she related what had happened the previous night.

“Someone warned you not to come here?” Floretta gasped. “Why, how could the news have gotten out?”

“I wish I knew,” Nancy admitted. “It would seem as though the walls have ears!” She lowered her voice. “Even now, someone may be listening to every word we say!”