As they stood outside the store, Nancy and Helen tried to comfort their friend. "It's a shame," Helen said.

"It ... it's the jinx again ..." Emily sobbed. "I should have known. Oh, poor d.i.c.k! All our plans are spoiled."

"I'm not so sure," Nancy said. "I have a feeling the thief subst.i.tuted these fakes for the real diamonds. I know it sounds funny ..."

"Huh!" Maud exclaimed. Turning to Nancy, she said, "An awful lot of funny things have happened since you came to Lilac Inn."

"That's enough, Maud!" Emily brushed away her tears. "I won't have you insulting my friends. Anyway, maybe Nancy's right."

"Oh, I forgot. Nancy's a famous detective!" Maud said sarcastically.

Helen and Nancy kept still with difficulty. Nancy wondered why Maud had become so antagonistic toward her.

In silence, the four reached Nancy's car. As the others got in, Nancy stopped a newsboy to buy a River Heights morning paper. Nancy opened her change purse. Simultaneously, a woman coming from the opposite direction jostled Nancy's arm.

The purse dropped to the pavement, scattering change in every direction.

"Oh, bother!" Nancy exclaimed.

Emily jumped out of the car to help retrieve the money. A moment later she gave a startled cry and pointed to the ground.

Lying beside the ten-cent piece was a small diamond brilliantly reflecting the sunlight!

The expression on Nancy's face brought Helen and Maud hurrying from the car. Emily picked up the diamond.

"Is this yours, Nancy?" she asked.

"N-no, I never saw it before," Nancy stammered, completely astounded.

Maud looked smug. "Try and make anyone believe that. It's one of your diamonds, Emily!"

Nancy was too horrified to speak. Helen came to her friend's defense. Glaring at Maud, she dedared, "If Nancy says she knows nothing about how the diamond got in her change purse, it's true!"

"Of course it is," Emily backed her up. "Oh Maud, why are you always so hateful?" Turning to Nancy, she said, "Someone has tried to throw suspicion on you. But why?"

"I don't know," Nancy replied. "If that's the case, I wonder if that woman who b.u.mped me might be in league with the jewel thief." To herself she added, "Maybe my impersonator is trying to throw suspicion on me!"

She paid the boy for the paper, then asked him and the others if they had noticed the woman. Unfortunately none of them had.

Nancy suggested that they have the new-found stone appraised, so the group re-entered Fabian's. The jeweler was surprised but obligingly put on his eyepiece.

"This is a perfect one-carat diamond!" he exclaimed. "If you're interested in selling, I'll be happy to make an offer."

"Not today, but I may be back." Emily smiled.

She and her friends returned to the convertible and Nancy headed for Lilac Inn. She speculated to herself on the imitation gems. "The thief learned the number and shapes of Emily's diamonds, and had the artificial ones made to match as closely as possible. Very clever."

Her thoughts were broken into by Maud asking Emily, "When are you going to tell d.i.c.k about the theft of your jewels?"

"When I get ready," was the cool reply.

As they turned into the Lilac Inn driveway, Emily sighed. "Aunt Hazel will be dreadfully upset to hear about the subst.i.tution of the gems."

"It'll put her to bed for a week," Maud prophesied unfeelingly. "Well, I'll see you all at lunch."

The noon meal was a rather uncomfortable one. Mrs. Willoughby was obviously dejected and ate little. Maud maintained an almost sulky silence. Nancy was preoccupied, though somewhat disappointed that John was not present. Also, a startling idea had come to her about the diamond in her purse: The noise which had awakened her during the night might have been made by an intruder leaving, perhaps by the bathroom window, after planting the diamond.

After luncheon Anna the waitress beckoned Nancy aside and handed her a note. "I just took this message from Mr. McBride on the phone. I was pa.s.sing the desk and answered the ring."

Nancy thanked the girl and read the message. "Nancy: I've found an important clue to the case. Come in your canoe to the dock where you saw the man with the crew cut. Wear your diving gear."

Nancy was intrigued. What was John's discovery? What kind of clue would necessitate underwater equipment?

Since Maud was there, Nancy merely told the others she had a date with John, saying, "Dad warned me not to go anywhere alone, but if John's with me, I'll be safe." Nancy then hurried to put on her bathing suit. Over this she slipped her rubber insulation suit. Then, carrying mask, aqualung, flippers, and an underwater camera on a strap around her neck, she went to the dock.

Soon Nancy was paddling her canoe down the river, scanning the sh.o.r.e ahead for the place near which she and Helen had capsized. She finally sighted the dock where Helen had seen the man in the rowboat. On the bank nearby was a blue canoe with Lilac Inn painted on its side.

"John!" called Nancy, looking about. No answer. Again Nancy called his name. Silence.

A little distance beyond the dock the girl noticed a man fishing from the beach. He wore a wide-brimmed straw hat. Cupping her hands, Nancy called out and asked if he had seen the young man who had come in the canoe.

"Yeah," the fisherman yelled in a nasal voice. "He went underwater a couple of minutes ago-dived into the middle of the river opposite his canoe."

"Thanks." Nancy was mystified. Why hadn't John waited for her to arrive? He knew it was dangerous for anyone to go skin diving alone.

Hurriedly she beached her own craft, donned her mask and aqualung, and slipped on the flippers. Then she swam out to the middle of the river.

She made a quick dive to begin her descent. As she straightened out, Nancy kicked with her fins and propelled herself with her arms. The water became darker and cooler as she descended. Small fish flitted by. Presently Nancy realized she was nearing the bottom. She estimated that the river was about twenty feet deep at this spot.

When she reached the muddy floor, she glanced about in every direction. There was no sign of John-only underwater plants and several large rocks.

Nancy swam cautiously and watched for crevices as she went forward. Every moment she expected to see John. Had he been underwater long? Had he met with a freak accident and been hurt? Even an expert skin diver can overestimate his physical abilities, she realized.

All of a sudden Nancy stopped abruptly. Her eyes widened and a chill went up her spine. Protruding from a ma.s.sive rocky overhang was something that resembled a shark's head!

"It can't be!" she gasped inwardly. "Sharks don't live in fresh water!"

The sinister shape, however, was far too large to be an ordinary fish. Nancy's fear gave way to curiosity, as the object remained stationary. She inched forward, holding the camera in front of her and c.o.c.king the shutter. Three more strokes and she would have a good view of the mysterious form.

One-two-Nancy was about to shoot, when a slight movement in the water caused her to whirl around. A spear came hurtling from behind a big rock to Nancy's right. The next moment the tip of the spear lodged in the lens of her camera!

CHAPTER VIII.

A Hoax Revealed NANCY'S heart thumped wildly as the spear quivered in her camera. Someone had tried to injure her! Why?

The girl detective's first instinct was to avoid further danger and rise to the surface as quickly as possible. But she paused to look around for the spear thrower. There was no sign of him.

"He may be getting ready for another attack, though," she thought. "I'd better not take a chance."

Gripping the camera, with the embedded spear, in both hands, she swam upward. At the surface, Nancy set out for sh.o.r.e and climbed to the dock. She glanced about for the fisherman, but he was not there.

Nancy removed her skin-diving gear, then examined the stainless-steel spear. It was the simplest type used for underwater fishing. The weapon was six feet long, with a sharp, thin tip. Nancy shuddered as she pulled it from the lens of her camera.

"I'd better go back to the inn," she thought. "Dad was right about it being dangerous for me to be alone."

Nancy had been preoccupied with her narrow escape. Now she suddenly remembered John. To her astonishment, the Lilac Inn canoe was gone. Had John surfaced while Nancy was underwater, and, not seeing her, returned to the inn? Also, she wondered whether John was the skin diver seen by the fisherman on the river.

Nancy's head whirled with theories as she pushed her canoe into the water and stepped into it. Recalling the strange, sharklike object, she thought, "Perhaps the spear thrower didn't want me to photograph the object? And was that what John meant about a clue?"

As Nancy tied up at the inn dock, she saw that the blue canoe was there. "Well, anyway, he's back."

As the young sleuth headed for her cottage, she heard Helen call. Nancy stopped, and Helen, Emily, and Mrs. Willoughby hurried forward. They stared aghast at the spear in Nancy's hand.

"N-Nancy! You've been in danger!" Helen gasped.

Nancy gave a wry smile. Just then John McBride, dressed in slacks and sports shirt, hurried toward the group.

Before Nancy had a chance to question him, John exclaimed, "Fine thing, Nancy Drew! Standing me up to go skin diving!"

"Standing you up?" Nancy retorted. "Where were you?"

"In the apple orchard," John replied. "Waiting for you, where I said I'd be."

Nancy shook her head. "There's been a horrible mix-up. I'll tell my story first."

When she had finished, John and the others expressed amazement and concern.

"Nancy," the young man said, "I didn't phone any message to you. Someone else did, apparently to keep you from seeing me in the orchard."

"What's all this about the orchard?" Nancy demanded.

John reminded her that at eleven o'clock she had hailed him from the patio. "I had just returned after failing to find the missing tools. You were wearing the pink dress you had on the night before. You said you had something to discuss with me, and asked if I would meet you at twelve-thirty in the apple orchard. I said I'd be glad to."

"Why, I was in Benton at eleven o'clock!" Nancy exclaimed. "I wasn't the girl you talked to!"

John looked dumfounded. "But the girl sounded and looked exactly like you." He added that he had taken a sandwich with him to the orchard, but left at one-thirty, deciding that Nancy had changed her mind.

Emily caught her breath. "Oh, Nancy! It must have been the girl who is impersonating you!"

John nodded somberly. "I'm afraid so. I sure was fooled. And someone wanted to get you away from here and even harm you, perhaps fatally!"

Helen looked distressed, and Mrs. Willoughby wrung her hands. "We must report all this to the police immediately. No one at Lilac Inn is safe."

Emily, though concerned, still held back. "Please-not until d.i.c.k gets home tomorrow. In the meantime, Nancy may solve the mystery."

Her aunt reluctantly agreed. Nancy had been silent, trying to fit the various elements of the puzzle together. It was evident to her that her "twin" had firsthand knowledge as to where she and others at the inn would be at certain times. Nancy was certain the girl's actions further indicated accomplices, and dangerous ones at that, judging from the spear thrower. Offhand, Nancy could not imagine anyone at the inn being involved in such scheming, not even Maud.

"Has anything else been stolen?" she asked abruptly.

"I haven't heard of any losses," Emily replied.

"What's the next move, Detective Drew?" Helen spoke up.

"I'm not sure," Nancy replied thoughtfully. "But I do agree, for the time being, it would be best not to have the police investigate either the river or the inn. Since our enemies apparently want me out of the way, it must mean they want to stay here. Let's hope we can catch them before they decide to leave!"

John changed the subject. "I'd like to investigate the place in the river where you saw that 'shark,' Nancy. Also, I'll try to find out who used the inn's canoe. See you later."

Nancy returned to her cottage. She put away the skin-diving gear and set the spear in the closet.

"I'd better hang on to this for evidence, even though there probably aren't any fingerprints on it except mine."

She took out her pink dress. It looked crisp and fresh.

"My impersonator sure is a quick-change artist," Nancy thought. "She must have let herself into the cottage while I was in Benton, and returned the dress while I was at lunch.

"I'd better lock every window and put a padlock on the door," she determined, selecting a green cotton dress to wear, "and also make some inquiries around here. Maybe someone saw a girl enter this cabin."

A newspaper Helen had bought that morning lay on a table. Absently Nancy looked at the first page. Suddenly her eyes widened. With interest she read a report about a red panel truck having been stolen two days before.

"An identifying mark," she read further, "is a chrome eagle ornament on the hood. The truck is believed to be in the vicinity of Benton."

Was this the truck which had forced her car into the ditch? Lieutenant Brice must have pursued her lead, and found out that the vehicle had been stolen.

"No wonder the driver was in such a hurry!" Nancy thought as she left the cottage.

On the way to join the others, Nancy had a sudden hunch. Mary Mason had left the inn abruptly, with the flimsy excuse that the place was haunted. "I never pursued that lead," the young sleuth told herself. "Anna was here then. Maybe she knows where Mary Mason is."

Before joining her friends, Nancy hurried to the kitchen to talk to Anna. The waitress was not there. A strange girl came up to her, and introduced herself as Jean Holmes. Jean's complexion was very pale, and her brown hair thick and combed close to her face. She wore heavy gla.s.ses.

"Can I help you?" she asked, smiling shyly.

Nancy inquired where Anna was. Jean said she had gone to the storage cellar. Nancy went downstairs and found Anna bringing out a supply of preserved fruits and jellies.

"Anna," Nancy said, "I'm trying to locate Mary Mason who used to work here. Do you know her home address?"

Anna shook her head, but said she would inquire among the other waitresses who had been there when Mary was.

"Thank you," said Nancy, and went to join her group on the patio.

She noticed that Maud Potter was not present. At the first opportunity, she asked Helen about this.

"Oh, Maud's been very exclusive. She stayed in her room all afternoon." Helen added dryly, "She hasn't been missed."