John put the object in his pocket, and Nancy had the feeling he had deliberately evaded her question.

  “I wonder if there are any distinguishing footprints,” he said, changing the subject.

  Nancy frowned as she looked at the soft earth. There was a print—a peculiar one which she recognized—clearly outlined. It had been made by a skin diver’s flipper. Nancy’s mind flashed back to the night before, when she had left for the lilac grove. John’s cottage had been dark. Maybe he had been sleeping. If not, where had he been?

  “John,” she said, looking the young man squarely in the eye, “were you skin diving last night?”

  CHAPTER XV

  The Underwater Rescue

  JOHN McBRIDE looked startled at Nancy’s sudden query. “No, I wasn’t skin diving,” he said, returning the girl’s direct look. “Why?”

  Nancy pointed to the marks on the ground. “They’re flipper prints,” she said. “There must be more! The jeep tread and these prints have to start and end some place.”

  John knelt down and studied the prints. “From the size, I’d judge these were made by a man.”

  Nancy suddenly recalled the similar prints she had seen and the distant sound of a motorboat she heard as she had approached the grove the previous night. She told John of this. “Perhaps,” she said, “whoever wore the flippers was to meet my impersonator and leave by boat.”

  “Or perhaps the diver was aboard but got out of the boat away from shore and swam underwater to avoid being detected,” John guessed.

  Nancy nodded and thought, “If this is the case, it eliminates Maud Potter as a participant in the rendezvous.”

  Nancy’s mind flitted over possible suspects. One of the gardeners? He could easily have skin-diving equipment without anyone knowing it.

  As Nancy and John walked toward the river, following the flipper treads, she asked, “John, do you know what ‘blue pipes’ are?”

  “Sure. Lilacs,” he said matter-of-factly.

  Nancy hesitated, then revealed her theory about the term being a code or a signal. “It could even mean Lilac Inn.”

  He raised his eyebrows in amazement. “Wow! Some shrewd deducing!” he exclaimed.

  John stopped suddenly and grasped Nancy’s arm. As the girl stared at him in surprise, he said excitedly, “Nancy! You’ve given me a terrific idea! I can’t explain until—well, someday you’ll understand.”

  Nancy’s curiosity was piqued. She naturally did not ask John what he meant. But she was certain that he was tackling some secret problem. What was it?

  By now the couple had reached the river. John pointed out three flipper prints in soft dirt patches along the bank.

  Nancy scanned the area. “I’d like to have a look underwater here,” she said. “John, would you like to make a skin-diving date?”

  John grinned. “You couldn’t keep me ashore.”

  The two returned to the inn. Nancy went first to the phone and called her father. Since she did not want to mention specific details in case someone was eavesdropping, she merely told him that “last night’s meeting was most interesting.”

  “I understand,” Mr. Drew said.

  “Also, Dad, is it all right if I go skin diving? John will accompany me.”

  Mr. Drew gave his permission. “Perhaps you’ll see some unusual fish,” he added meaningfully.

  “Could be, Dad. I’ll let you know.”

  After Nancy had said good-by, she and John confided their plan and the reason for it to Helen, Emily, and Dick.

  “All right,” said Emily worriedly, “but watch out for spear throwers.”

  Soon Nancy and John, ready for skin diving, were back at the riverbank. They had decided to search underwater from the area of the flipper prints to the place Nancy had spotted the sharklike object.

  They adjusted their face plates and tanks, and then they descended. Down—down they went, finally reaching the muddy bottom.

  Their eyes darted here and there, observing schools of little fish; but nothing out of the ordinary came to sight. Nancy and John continued on, until they reached the place where Nancy had been before. They linked hands and walked cautiously along the river bottom.

  Nancy pointed out the rocky overhang from which she had seen the shark shape projecting, John nodded.

  To Nancy’s disappointment, there was no sign of anything resembling the mysterious object. What had it been, she puzzled? A sunken boat that might have since drifted away?

  Suddenly John stumbled and dropped Nancy’s hand. Startled, she saw that his foot was wedged between two rocks obscured by weeds. He bent down and tugged, but to no avail.

  At once Nancy went to his assistance. First, she pulled away the plant life surrounding the rocks. Then gently she tried to ease John’s foot loose. It would not budge.

  Nancy worked desperately to dislodge one of the rocks. Finally, with John’s help, she succeeded in moving one of the stones. John’s foot was free!

  Exhausted, the couple rose to the surface and swam toward shore, gulping in fresh air. As soon as they sat down on the bank, John thanked Nancy for coming to his rescue. “You’re a wonderful partner to have around, Nancy—sleuthing or skin diving,” he said.

  Nancy smiled. “Thanks, John. Let’s have a look at your foot and see if it’s injured.”

  John sighed. “Yes, Nurse.”

  They found that his foot was merely scraped. He and Nancy went underwater again to do some more sleuthing. But they uncovered nothing suspicious. Baffled, they swam back to their starting point and walked toward the inn.

  On the way, Nancy saw Gil Gary trimming a hedge nearby. She and John went over to him.

  “Do you happen to know anyone else around here who skin-dives, Gil?” Nancy asked.

  The gardener did not look up, and continued his trimming. “Naw,” he muttered. “River bottom’s too muddy. It—”

  He broke off. Nancy felt a surge of excitement. Why did Gil assume she was referring to the river? And did he know of its muddy condition from personal experience? Why had he not finished his answer?

  “I suppose,” she said, “some people prefer to travel by canoe.” Nancy looked directly at the dock where one of the inn’s canoes was tied up.

  “S’pose so,” Gil replied shortly.

  John now stepped forward. “By the way, Gil, have you or Hank noticed any more tools missing lately?”

  “Naw.” The gardener shook his head.

  John shrugged casually. “Just wondered, because Miss Drew and I came across a funny gadget this morning. Sort of like a can opener. Sound familiar?”

  “No!” the gardener snapped. He flung his shears to the ground. “I’m goin’ for lunch,” he said, and retreated hastily.

  Nancy and John exchanged triumphant glances. “He’s nervous about something, all right,” John said.

  “He certainly doesn’t act like an innocent person,” Nancy reasoned.

  There was just time before luncheon for Nancy and John to report in private to their three young friends.

  When Dick heard of the gardener’s reaction to Nancy’s queries, he frowned. “Maybe I should have a talk with him myself,” he said.

  Nancy advised against this action for the present. “If Gil is connected with the diamond theft, we may learn through him who else is involved,” she pointed out. “And, perhaps, the identity of my double.”

  “You mean, all the culprits might be trapped at once?” Helen asked, and Nancy nodded.

  As Nancy sat down at the table with the others, Jean came over. “Thanks again for the ride, Miss Drew,” she said in her shy way. “It was real helpful.”

  At this moment Maud Potter entered the room. Jean quickly bent over and whispered to Nancy, “Don’t forget! Watch out for that trouble-maker.”

  Nancy did not know what to think. She disliked Maud, but felt it was unfair to accept Jean’s claim without proof. “Don’t trust an informer too far,” her father had once said.

  The social director took
her place. Looking at Emily, she announced, “Your aunt has a splitting headache and won’t be down.”

  “Oh, poor dear.” Emily jumped up. “I’ll go see—”

  “I wouldn’t disturb her,” Maud interrupted officiously. “She’ll feel better after some rest.”

  Emily’s eyes blazed. “If I want to see my aunt, Maud, I shall. I’m sick and tired of your meddling. Dick and I are paying you to be social director—and—and nothing else!”

  There was dead silence at the girl’s outburst. Then Maud gasped. “Well! That’s all the thanks I get.”

  “Thanks for what!” Emily stormed. “Keeping Aunt Hazel under your thumb and being unpleasant to my guests?”

  By now everyone in the dining room—waitresses and patrons—were staring in Emily’s direction. Dick tried to intervene. “Em, calm down,” he begged. “We’ll discuss it later.”

  But Emily, overwrought, paid no attention. “I don’t care. I’ll give up Lilac Inn rather than see Aunt Hazel unhappy. I wouldn’t be surprised, Maud Potter, if you’re responsible for the awful things that have happened here!”

  An almost bewildered look came over Maud’s flushed face. She started to protest, “I most certainly did not—”

  Emily did not allow her to finish. “Furthermore,” the girl went on, “I’m going to notify the police about all my suspicions regarding the diamonds immediately.”

  At this point Nancy happened to notice that Jean Holmes was taking in the scene with avid interest. For a fleeting moment the sleuth detected a hard, calculating look replacing Jean’s usually shy expression. But the next moment the waitress picked up a tray and went toward the kitchen.

  In the meantime, Maud had also risen. “By all means call the police. It’s about time they learn the truth,” she said, with a scornful glance at Nancy. Declaring she had lost her appetite, the woman left the room.

  Pale and trembling, Emily sat down. “I’m sorry,” she said weakly. “I just couldn’t take Maud’s arrogance another minute.”

  “I don’t blame you,” Helen spoke up sympathetically, then whispered, “At least Maud didn’t act as if she were mixed up with the theft of the diamonds.”

  “That’s right,” Dick conceded. “But where do we go from here? Unless this mystery’s cleared up, we may not be able to open the inn in July. Also,” he added glumly, “Emily and I might have to postpone our wedding.”

  “Oh, no!” Emily wailed.

  Dick said he could foresee no other course of action. His funds were low, and if he and Emily were to make a success of the resort, the necessary outdoor work must be completed. A pool and tennis courts, yet to be built, had been especially featured in his publicity campaign.

  “I’ve already mailed out thousands of brochures,” he said.

  “Yes, and we’re booked almost solid for summer reservations,” Emily said unhappily. “Oh, Nancy, what shall we do? I hate to give up hope of getting my diamonds back.”

  Nancy replied firmly, “I’m not giving up. If you agree, Emily and Dick, there are a few more angles of this case I want to investigate. And if you don’t mind, I’d like to tell Lieutenant Brice the whole story.”

  The engaged couple readily consented. “Nothing matters now except finding out the truth,” Emily said.

  After lunch Nancy drove to Benton. For privacy, she telephoned the State Police officer from a booth in the drugstore there. When Nancy had finished her account, he assured her he would do all he could to turn up possible new leads to Nancy’s impersonator. Then Nancy called Chief McGinnis. The typed envelope, he said, had brought no results.

  “I’ll confer with Lieutenant Brice about happenings at Lilac Inn. By the way, no luck yet in finding the stolen truck.”

  Nancy’s next call was to her father. Mr. Drew confessed alarm upon hearing the details of his daughter’s meeting with her double. “No telling what she and her accomplices may be up to,” he warned. “But whatever you do, Nancy, don’t overstep anyone’s legal rights.”

  “I’ll remember.”

  By the time Nancy returned to the inn, it was late afternoon. The sky had filled with black clouds, and the air was close and oppressive. “There’s going to be a thunderstorm,” Nancy thought as she entered the lobby.

  No one was in sight. But just then Mr. Daly came from his office. He said that nothing had been found to account for the quakelike vibrations.

  “I’m afraid, Mr. Daly,” Nancy said, “that the cause is man-made. How, I don’t know yet.”

  The former owner of the inn was shocked. “To think this fine building must endure such treatment!” He told Nancy that the inn had been built in 1760 by an English family, and had catered to both stagecoach and river travelers. The inn had passed from one generation of the original family to the next. “Some people said that Lilac Inn was a refuge for slaves who had escaped from the South.”

  “Maybe that’s why the secret room was built,” Nancy remarked. “Who owned the inn previous to you?” she asked.

  “A Spaniard named Ron Carioca who’d lived in the West Indies. It was he who planted the beautiful lilac tree—for good luck—outside the front entrance.”

  Just then Mr. Daly’s phone rang, and he excused himself to answer it. Nancy walked on into the dining room and looked out the bay window. The sky was getting darker each minute.

  “Oh, hello, Miss Drew.” The voice was Jean Holmes’. She carried a large vase filled with yellow iris and reddish-purple lilacs, which she set on the window sill.

  “You seem to like flowers, Jean,” Nancy observed. “That’s a pretty combination: iris and ‘blue pipes.’ ”

  “ ‘Blue pipes’?” Jean echoed. “What made you use that expression?”

  “It’s different,” Nancy said nonchalantly.

  Did the waitress seem suddenly ill at ease, or was it Nancy’s imagination? Before the young sleuth could decide, there was a loud clap of thunder, followed by the banging of several shutters. As Jean and Mr. Daly hurried to shut the dining-room windows, Nancy saw John and Dick dash across the side lawn toward the inn.

  Rain came pouring down in silvery sheets. There was another resounding thunderclap, then a vivid flash of lightning. A splintering, crashing sound followed.

  “Oh!” Jean shrieked. “The inn’s been struck!”

  CHAPTER XVI

  A Letter

  THE crash had come from the front of the inn. Everyone raced through the lobby to peer outside.

  “Oh!” Nancy cried. “The historic lilac tree is down.”

  The lovely “tree of good fortune” had fallen onto the lawn, splintered and charred.

  “More bad luck!” Emily said mournfully.

  Suddenly Maud burst out, “This is the last straw! I’m fed up with a place full of thieves, weird noises, bombs, a trembling building—I quit.”

  She turned a scathing look on Mrs. Willoughby. “You got me into this. Thanks for nothing! I’ve found a better job on my own!”

  Emily’s face was expressionless as Maud snapped open her purse and fumbled through its contents. She drew out a letter and flourished it.

  “This is an offer of a position I received today from the Hotel Claymore in River Heights. I’ve already accepted it,” Maud stated. “Emily, I didn’t go to the employment agency just to find you a waitress, but to find a decent job for myself. But I asked the manager not to say I had been there.”

  With dignity Emily said, “Maud, Dick will write a check for whatever salary we owe you.”

  With a triumphant air Maud marched upstairs. Emily looked around anxiously. The waitresses and cooks had gathered in a corner of the hall. Obviously they had not missed a word of what had been said.

  Nancy sensed what her friend was thinking: that the employees were probably suspicious about the fire. Now that Maud had mentioned the bomb, all of them might become alarmed enough to give notice. Prospects for Lilac Inn’s success would indeed be dim.

  “I must help Em and Dick before it’s too late,” Nancy told h
erself determinedly.

  As the rain abated and the sky began to brighten, the men went outside to examine the fallen lilac. Nancy now turned to Mrs. Willoughby, who seemed almost in a daze. “Perhaps you’d better sit down and rest,” she said kindly.

  Emily’s aunt gave a great sigh. “I will. Please come with me to Emily’s office,” she asked the three girls.

  When they were seated, Emily said, “Aunt Hazel, was Maud Potter threatening you in some way?”

  “I’m afraid so,” Mrs. Willoughby replied wearily. “Actually I believe she wouldn’t have carried it out. But I couldn’t be sure—”

  To the girls’ dismay, the woman broke down and sobbed. Nancy patted her shoulder. “Won’t you tell us about it?”

  Regaining composure, Mrs. Willoughby nodded. “I feel terrible. When I brought Maud here, I thought I was helping Emily and Dick. But it’s turned out just the opposite.

  “Anyhow,” she went on, “I met Maud a year ago at a party in River Heights. We became friendly—attended the theater and so forth. Maud seemed very pleasant and good company at the time. And I also felt sorry for her.”

  “Sorry?” Helen echoed.

  Mrs. Willoughby explained that Maud’s husband had died several years before, leaving her penniless. Since then, she had worked at various resorts, but not very long at any one.

  “When Maud heard about Lilac Inn, she persuaded me that, with her experience, she’d be ideal as social director. But soon after her arrival here, she asked me to lend her a large sum of money—claimed to have a lot of unpaid bills which her salary wouldn’t cover. Maud became angry when I refused, but she continued her demands for money.”

  Emily interrupted, “Aunt Hazel, why didn’t you tell us she was bothering you? Dick would have asked her to leave.”

  “Maud insinuated that if I tried to force her to leave, she would say that—that I had stolen your diamonds, Emily, by getting them from the bank weeks ago, and substituting the fake stones!”

  “How dreadful!” Nancy cried out, and Emily added fiercely, “That awful woman! But, Aunt Hazel, we never would have believed her.”