"He was tailing me!" Nancy thought.

She had never seen the man before and won- dered why he was trailing her. She was eager to tell her father, but found that he had invited a client to dinner. By ten o'clock, after the caller had gone, she had stopped thinking about the incident.

Before retiring, father and daughter sat down in Mr. Drew's bedroom to discuss the mystery.

"Isn't Emily Foster our best lead yet?" Nancy asked.

Mr. Drew did not answer; in tact, for several seconds he had not been paying strict attention to Nancy's conversation. Now, so suddenly that the young detective was startled, he tiptoed to the door and yanked it open.

A man in a brown suit crouched just outside.

Thrown off balance, he fell forward into the room.

CHAPTER XI.

A Warning.

"So you were eavesdropping!" Mr. Drew said sternly as he pulled the man to his feet.

"No, that's not true!" the fellow stammered.

After recovering his balance, he tried to retreat.

Mr. Drew blocked the doorway. "Sit down!"

he ordered the man into the room. "We want to talk to you."

Nancy recognized the man as the one who had followed her.

"What were you doing outside my door?" Mr.

Drew asked him sharply.

"Nothing," he replied in a sullen voice. "I thought this room belonged to a friend."

"That's hard to believe, but easy enough to check. What's his name?"

"None of your business."

"I can turn you over to the police."

Nancy spoke up. "I can report to them that you trailed me today!"

The stranger squirmed uneasily in the chair.

"You can't prove anything!"

"This man followed you today?" Mr. Drew asked his daughter in surprise.

"Yes. I forgot to tell you about it."

"That settles it," the lawyer said. "We'll turn him over to the police for questioning."

"No, no! Don't do that! I'll tell anything you want to know-except my name," the stranger said.

"Very well." The lawyer nodded. "Why were you following my daughter?"

"Because I was paid to do it."

"By whom?"

"I don't know the guy's name."

"What were your instructions?"

"To make a complete report on where Miss Drew went, whom she talked to, and what she did."

Mr. Drew turned so that the man could not see him full face. With a wink and a quick movement of his hand he signaled Nancy to step into the ad- joining room. For a moment the young detective was puzzled. Then it dawned upon her that her rather wanted her to slip quietly downstairs and arrange to have the stranger followed.

"So you won't tell us your name?" Mr. Drew repeated, facing the stranger once more and walk- ing up so close to him the man could not see Nancy.

"No. I won't," the man replied.

Nancy stole noiselessly into the adjoining room.

She hastened downstairs and used a public tele- phone to call police headquarters. After identify- ing her father and herself, she said, "Please send a plainclothesman at once. I'll meet him in the lobby and explain everything when he arrives.

How will I know him?"

"He'll pretend to have a bad cold," the officer said.

Nancy was worried that the detective might not reach the hotel in time. But in less than five min- utes a man entered coughing uncontrollably. She told him why he had been called and asked him to trail the eavesdropper.

"Here he comes now!" she whispered as the brown-suited stranger emerged from an elevator.

"He must not see me!"

She hid behind a pillar and noticed with satis- faction that the eavesdropper did not realize he was being followed from the hotel. Then she went upstairs.

Mr. Drew praised his daughter tor having in- terpreted his signals correctly. "By the way," he asked, "have you called Hannah since we left home? There may be some messages for us."

At once Nancy dialed the Drew number. Han- nah Gruen answered.

"I'm glad you phoned," she said. "I tried to reach you in Hampton, but you had already left."

"Is anything wrong?"

"Mrs. Fenimore called this morning and wanted to see you."

"Mrs. Fenimore?" Nancy echoed in curiosity.

"Did she say why she called?"

"She wouldn't tell me over the phone," Han- nah resumed. "When I told her you weren't home, she said you had to be warned to be care- ful."

"Careful of what?"

"She thinks you're in danger. Oh, Nancy, I'll be so relieved when you're home again safe and unharmed."

"We'll be back tomorrow," Nancy a.s.sured her.

"Don't worry."

After completing the call Nancy speculated on why Mrs. Fenimore thought the young detective was in danger. Could the woman have learned that Nancy was to be shadowed? It was too late, she decided, to call Mrs. Fenimore. "I'll see her tomorrow."

Nancy and her father waited until midnight to hear from the plainclothesman. When he failed to return to the hotel, they telephoned head- quarters. The officer had not checked in yet.

In the morning there was no word either, so Mr. Drew requested that a full report be sent to him in River Heights.

After Nancy arrived home in the afternoon, she lost no time calling on Mrs. Fenimore. The woman was reclining on a couch. She was ex- hausted from strain and worry.

"I shouldn't have become so upset," she said.

"But Mr. Hector's att.i.tude always disturbs me."

"He came to see you?"

"Yes. I had a dreadful session with him. He asked me so many questions."

"About your sister?"

The woman nodded. "He wanted to know it I had hired someone to search tor Julie."

"Did you mention my name?"

"Well, I did say you had offered to help me,"

Mrs. Fenimore admitted, "though I feel unhappy about having told him. From the way he behaved, I'm sure he intends to make trouble tor you."

"I'm not afraid of Daniel Hector," Nancy said.

"Oh, but you should have heard him talk! He said he wouldn't let anyone meddle in his affairs.

He acted as if Heath Castle belongs to him!"

"Mr. Hector is worried," Nancy commented, frowning. "His remarks and the fact that he came to talk to you regarding your sister indicate a guilty conscience."

"Would you risk going to Heath Castle again, Nancy?"

"I would if I could accomplish something," the young detective said. "But I believe the mystery may be solved in another way."

She thought it best not to tell Mrs. Fenimore about the possibility that her sister might have been crippled as a result of an automobile acci- dent. She merely said there was an interesting new lead to follow, one which would not involve her coming in contact with Daniel Hector.

Later, at home. Nancy reviewed the develop- ments in the mystery. Intruders prowling around the Heath estate were looking for something im- portant. She had heard them mention the clue in a stone wall and unnamed items they had already found. Where did Hector fit in? Were they all working together? What-if anything-did the search have to do with Juliana's disappearance?

"And then there's the man who was eavesdrop- ping," Nancy thought as she opened the top drawer of her dresser to get a handkerchief. There lay the torn note she had found in the debris at the Heath factory. In the recent excitement she had forgotten about it, "This may be my most valuable clue," she chided herself. "I must try to figure it out."

She sat down to piece out the message. Just then the telephone rang. The caller was George who wanted to know how the detective work was progressing.

"I have a clue to your stolen clothes," Nancy said, and told of the shirt at Mrs. Hooper's.

"Why, the nerve of that woman!" George cried indignantly "I'm going there at once and demand that she return my property!"

"You can't prove anything, George," Nancy said. "Better forget the matter for the time being, and come over here. I have lots to tell you. Bring Bess along."

"Be there p.r.o.nto," George replied and hung up.

"If it was really Teddy who took those clothes,"

Nancy reasoned, "what was he doing in the Heath gardens?" She was still trying to figure this out when her friends arrived. Nancy told them every- thing that had happened on her trip.

"Poor Juliana!" Bess said. "How dreadful to have her career cut off that way!"

"I wish you could have found the nurse Emily Foster," George added. "Well, what are you going to work on next?"

"This note, or rather, this piece of a note."

Nancy produced the bit of paper and the girls pored over it for some time, each with a pencil and paper, trying to fill in the lines to form a logi- cal message. Bess was the first one to claim having pieced together the missing words.

"Listen to this," she said. "I've got it!

" 'Dear C, Some place is the se- cret which I hid in a wall. I want to be famous. If I can sell it, I will be worthy of you.' "

George scoffed. "If he was going to sell it, why would he hide it in a wall?"

"Well, it fits the missing words," Bess defended herself.

"One guess is as good as another," Nancy said, then she stared thoughtfully at the paper before her. Suddenly she jumped up from the chair and said, "The solution to this mystery might be right in this very house!"

Without explaining her strange remark, Nancy ran from her room and down the stairs. A few minutes later she returned with a large book.

"How in the world are you going to find Juli- ana with that?" George asked.