Part 6

At the adjoining table the two men abruptly hauled to their feet. Paying their bill they quitted the restaurant.

"Let's leave, too," suggested Penny. "I should like to see where they go."

Jerry pushed his plate aside. "Suits me," he agreed. "Even my cast-iron stomach can't wrestle with such food as this."

He paid at the cash register and they went out into the night. Penny looked about for the two men and saw them walking toward the river.

"Hold on," said Jerry as she started to follow. "Tell me what all the excitement is about."

Tersely, Penny repeated the conversation she had overheard.

"They're tough looking hombres all right," Jerry admitted. "Likely as not mixed up in some dirty business. But to say they're involved in the Kippenberg affair--"

"Oh, Jerry," Penny broke in impatiently, "we'll never learn anything if we take that attitude. We must run down every possible clue. Please, let's see if they go down to the river."

"We ought to be getting our story back to the office," Jerry reminded her. "If we miss the last edition there will be fireworks."

"It will only take a minute," Penny insisted stubbornly. "If you won't come with me, then I'm going alone!"

She started away and the reporter had no choice but to follow. A narrow, well-trod path led down a steep slope toward the river. Long before they came within sight of it they could hear the croak of bullfrogs and feel the damp, night mists enveloping them like a cloak.

Drawing closer to the two men, Penny and Jerry slackened pace and moved with greater care. But if they hoped to learn anything from the conversation of the pair ahead they were disappointed. The talk concerned only the weather.

Reaching the banks of the river, the two men boarded a sturdy cabin cruiser which had been moored to a sagging dock.

"It's the very same boat," Penny whispered jubilantly. "I knew I wasn't mistaken."

"Even so, what does that prove?" demanded Jerry. "It's no crime to run a motorboat near the Kippenberg estate. The river is free."

"But you must admit there _is_ other evidence. Oh, why can't we follow them? We might learn something really important."

"We're not going off on any wild chase tonight," stated Jerry sternly. "Come on, it's home for us before your father sends a police squad to search for his missing daughter."

"You're losing a golden opportunity, Jerry Livingston."

"Listen, by the time we located a boat those men would be ten miles from here. They're leaving now. Use your head."

"Oh, all right," Penny gave in. "We'll go home, but I'll bet a cent you'll be sorry later on."

She waited until the cruiser was lost to view in the darkness and then allowed the reporter to guide her back up the steep path.

"At least let's try to find out who the men are," Penny urged as they came near the cafe. "The restaurant owner might know."

More to please her than for any other reason, Jerry said that he would inquire. He re-entered the cafe, returning in a few minutes to report that the proprietor had never seen either of the men before.

"And now let's be traveling," he urged. "We've killed enough time here."

During the remainder of the ride back to Riverview, Penny had little to say. But long after she knew Jerry had forgotten the two boatmen she kept turning their conversation over in her mind. She only wished she might prove that her theories were not ridiculous.

Presently, the automobile drew up in front of the Parker residence.

"Won't you come in, Jerry?" Penny invited. "Dad may wish to talk with you about the case."

"I might stop a minute. I have a question or two to ask him."

The door of the house swung open as Penny and the reporter crossed the front porch. Anthony Parker stood framed in the bright electric light, a tall, imposing figure.

"That you, Penny?"

"Yes, Dad."

"I'm glad you're home safe," he said, not trying to hide his relief. "Mrs. Weems and I have both been worried. It's going on nine o'clock."

"So late? Didn't Louise telephone you?"

"Yes, she said you had gone on to the Kippenberg estate. Knowing you, I worried all the more. What mischief did you get into this time, Penny?"

"None. Jerry took care of that!"

Mr. Parker held the door open for his daughter and Jerry to pass through. "Have you had your dinners?" he asked.

"We stopped at a roadside cafe, Dad. But the food was horrible. We didn't even try to eat it."

"Mrs. Weems can find something for you, I'm sure. She's upstairs."

"Don't call her just yet," said Penny. "First, we want to tell you what we've learned."

Mr. Parker listened attentively as Penny gave a detailed account of her visit to the estate, the finding of the silk hat, and finally of her encounter with the two boatmen at the river cafe.

"I might have learned a lot more if only Jerry hadn't played grandmother," she said crossly. "He refused to follow the boat down the river--said it would only be a wild chase."

"Jerry, I'm glad you had will power enough to overrule her," declared Mr. Parker. "The possibility of those men being connected with the Atherwald case seems very vague to me."

"Dad, you should have heard what they were saying! The one man drew a design on the tablecloth and asked his companion what he thought of the route. They talked about a quick get-away to the sea."

"The men may have been fugitives," Mr. Parker commented. "But even that isn't very likely."

"They spoke of being uneasy about a certain job they had agreed to do," Penny went on earnestly. "They mentioned a girl and said that a fellow named Dietz would bear watching."

Mr. Parker leaned forward in his chair. "Dietz?" he questioned. "Are you certain that was the name?"

"Yes, I heard it clearly."

"I don't see how there could be any connection," Mr. Parker mused. "And yet--"

"Where did you hear the name before, Dad?" Penny asked, all eagerness.

"Well, DeWitt has been digging up all the facts he can about James Kippenberg. As it happens, the man once had a business associate named Aaron Dietz who was dismissed because of alleged dishonesty."

"Then there must be a relationship!" Penny cried. She whirled triumphantly to face the crestfallen reporter. "You see, Mr. Jerry Livingston, my theory wasn't so crazy after all! Now aren't you sorry?"

CHAPTER 14 _THE STONE TOWER_

Louise Sidell was washing the breakfast dishes when Penny walked boldly in at the back door.

"Don't you ever answer doorbells, Lou?" she demanded. "I stood around front for half an hour, ringing and ringing."

"Why, hello, Penny. I didn't hear you at all," apologized Louise. "The radio is on too loud. I see you reached home last night."

Penny picked up a towel and began to dry dishes. "Oh, yes, and did I have a day!"

"What happened after you left Andover?"

"It's a long story, so I'll begin at the end. Last night, coming home with Jerry we stopped at a cafe along the river. Guess whom we saw!"

"Knowing your luck, I'd say Charlie Chaplin, or maybe the Queen of England."

"This particular cafe wasn't quite their speed, Lou. Jerry and I saw that same boatman I told you about!"

"The fellow you saw cruising about the Kippenberg estate? What's so remarkable about that?"

"It just happens I've dug up other evidence to show he may know something about Grant Atherwald's disappearance," Penny revealed proudly. "Jerry and I overheard a conversation. It seems this man and a companion of his are mixed up with another fellow named Aaron Dietz."

"Which doesn't make sense to me," complained Louise, scrubbing hard at a sticky plate.

"Aaron Dietz was a former associate of James Kippenberg. Dad said he probably knew more about the Kippenberg financial affairs than any other person. Oh, I tell you, Jerry feels pretty sick because we didn't follow the men last night! Dad assigned him to try to pick up the trail today. He's chartered a motor boat and will patrol the river."

"If you don't mind," said Louise patiently, "I'd like to hear the first part of the story now. Then I might know what this is all about."

Talking as fast as she could, Penny related everything which had happened since she had taken leave of her chum at Andover.

"Which brings me to the point of my visit," she ended her tale. "How about going out there with me this morning?"

"To the Kippenberg estate?" Louise asked eagerly.

"Yes, we may not be able to get across the river, but I mean to try."

"You know I'm wild to visit the place, Penny!"

"How soon can you start?"

"Just as soon as these stupid dishes are done. And I ought to change my dress."

"Wear something dark which won't attract attention in the bushes," advised Penny. "Now get to working on yourself while I finish the dishes."

Louise dropped the dishcloth and hurried upstairs. When she returned ten minutes later, her chum was swishing the last of the soapsuds down the sink drain. Another five minutes and they were in Penny's battered car, speeding toward Corbin.

The sun rode high in the sky by the time they came within view of the drawbridge. Noticing that a press car from a rival newspaper was parked at the end of the road, Penny drew up some distance away. She could see two reporters talking with the old watchman.

"Evidently, they're having no luck in getting over to the estate," she remarked.

"Then what about us?"

"Oh, we have our own private taxi service," Penny chuckled. "At least I hope so."

Taking a circuitous route so they would not be noticed by the bridgeman, the girls went down to the river's edge. Far up the stream Penny saw the familiar rowboat drifting with the current. At her signal the small boy seized his oars and rowed toward shore.

"I was here at eight o'clock just as you said," he declared. "That fellow up there by the bridge offered me a dollar to take him across the river. I turned him down."

"Good," approved Penny.

"Do you want to go across the river now?" the boy asked.

"Yes, please." Penny stepped into the boat and made room for Louise. "Keep close to the bank until we are around the bend. Then I'll show you where to land."

"I guess you're afraid someone will see you," the boy commented.

"Not exactly afraid," corrected Penny. "But this way will be best."

The boat moved quietly along the high bank, well out of sight of those who stood by the drawbridge.

"The cops were here this morning," volunteered the boy as he pulled at the oars.

"You saw them visit the estate?" Penny questioned.

"Sure, there were four of 'em. They drove up in a police car and they made old Thorndyke let the bridge down so they could go across."

"Are the policemen at the estate now?"

"No, they left again in about an hour. What do you suppose they wanted over there?"

"Well, now, I couldn't guess," replied Penny. "Like as not they only wished to ask a few questions. Are the Kippenbergs at home?"

"I saw Mrs. Kippenberg drive away right after the police left."

"And her daughter?"

"I guess she must be still there. Anyway, she wasn't in the car."

The boat rounded the bend, and Penny pointed out a place on the opposite shore where she wished to land.

"Shall I wait for you?" the boy asked as the girls stepped from the craft.

"Yes, but not here," directed Penny. "You might row back to the opposite shore and keep watch from there. We ought to be ready to leave within at least an hour."

The roof top of the Kippenberg house could be seen towering above the tall trees. But as the two girls plunged into the bushes which grew thickly along the shore they lost sight of it entirely.

"I hope," said Louise uneasily, "that you know where you are going. It would be easy to lose one's self in this jungle."

"Oh, I have my directions straight. We should come out near the lily pool at any minute."

"What do you hope to gain by coming here, Penny?" Louise inquired abruptly.

"I thought I would try to talk with Miss Kippenberg again. There's an important question I forgot to ask her yesterday. Then I wanted to show you the estate, especially the lily pond."

"Is there anything unusual about it?"

"I'll let you be the judge," Penny answered. "We're almost there now."

They came in a moment to a path which made walking much easier. Penny went in advance of her chum. Suddenly she halted.

"See what is ahead, Lou! I never saw that thing before."

She stepped to one side so that Louise might see the tall stone tower which loomed up against a background of scarlet maples.

"How curious!" murmured Louise.

"This isn't the only queer thing I've found on the estate."

"What purpose could the tower have?" speculated Louise.

"Decoration, perhaps," replied Penny, moving forward again. "Or it might have been built for a prison."

"Listen, you have too many different theories about Grant Atherwald," laughed Louise. "Why don't you get one and stick to it?"

"My mind is always open to new possibilities and impressions."

"I'll say it is," agreed Louise. "I suppose you think Mrs. Kippenberg is keeping young Atherwald a prisoner in yonder tower?"

"Well, no, but you must admit it would make a lovely one. So romantic."

"Are you trying to kid me?" Louise demanded.

Penny smiled broadly as she stared up at the tower which rose perhaps twelve feet. Like every other building on the estate it had been built to resist the ages. High above her head a circular window had been cut in the wall and there was a heavy oaken door.

Reaching for the knob, Penny turned it. Then she pressed her shoulder against the door and pushed with her entire strength.

"Locked!" she announced.

"Then we won't learn what is inside after all."

"Yes, we will," declared Penny. "You lift me up and I'll peep in the window."

"You only weigh a ton," complained Louise.

She obligingly raised Penny up as high as she could.

"Look fast," she panted. "What do you see?"

"Not much of anything."

"I can't hold you forever," Louise said, and released her hold. "Didn't you see anything at all?"

"Just a lot of machinery."

"Tools, you mean?"

"No, an electric motor and something which looked like it might be a pump. Oh, I get it now!"

"Get what?" demanded Louise.

"Why, the idea of this tower. It must be used as a pump house. I wondered how the lily pool was ever drained and this must be the answer."

"You didn't see any prisoners chained inside?" Louise teased.

"Not one. Well, let's be getting on to the lily pond. It must be somewhere close."

Louise could not understand why her chum was so determined that she should see the pool. But since Penny seldom did anything without a purpose, she speculated upon what might be in store. She knew from the girl's manner that certain facts had been withheld deliberately to make this visit the more impressive.

"Here we are," said Penny as they came to the clearing. "What do you think of it?"

Louise was aware of a deep sense of disappointment as she gazed at the lily pool.

"I really don't see anything so remarkable about it, Penny."

"This was the place where I found the wedding ring. And there were footprints indicating that a struggle probably took place."

"I read all that in the paper," Louise said. "From the hints you've been passing out, I thought you brought me here to show me something mysterious."

"Go close to the pool."

"What for, Penny? You want to push me in?"

"Oh, you're too suspicious! Go on and look."

Louise went to the edge of the pool and peered down into the water.

"I don't see anything."

"You will in just a minute. Keep looking."

Louise was more than half convinced that Penny meant to play some prank, but she dropped down on her knees so her eyes would be closer to the water.

"Why, I do see some large object on the floor of the tank!" she exclaimed after a moment. "What is it, Penny?"

"An alligator."

Louise gave a smothered scream and drew back from the pool's edge.

"I--I might have fallen in. You ought to be ashamed of yourself!"

"I only wanted you to get a nice thrill," Penny grinned. "Pretty fellow, isn't he?"

"I didn't really see him," Louise admitted.

Overcoming her fear, she again leaned over the edge of the pool but with great caution. This time she could make out the alligator's form distinctly.

"Horrible!" she shuddered. "I wish you hadn't brought me--"

Her words ended in a little wail as a tiny object splashed into the water directly beneath her.

"My cameo pin!" she cried. "Oh, Penny, it slipped from my dress and now it's gone!"

CHAPTER 15 _A CAMEO PIN_

In dismay, the two girls watched the trinket settle slowly to the bottom of the pool.

"Oh, my beautiful pin," moaned Louise. "Aunt Lucinda gave it to me for my birthday. I wouldn't have lost it for anything in the world."

"I guess it was my fault," Penny said self-accusingly.

"No, it wasn't. I must have been careless about fastening the clasp. When I leaned over it slipped off. Well, it's gone, and that's that."

The cameo pin had fallen into the deepest part of the pool not far from where the alligator lay. The girls were unable to see it plainly because of the lily pads and plants which cluttered the water.

"If that old alligator would just behave himself we could wade in and get it easy," Penny said.

"Fancy trying it!"

"I'm afraid he would take special delight in snapping off an arm or a leg. And we don't dare ask anyone to help us get the pin or we'll be ejected from the grounds as trespassers."

"We may as well forget about it, Penny. Come along, I'm sick of this place."

"No, wait, Louise. We might be able to fish it out with a stick."

"I don't think we'd have a chance."

"Anyway, it will do no harm to try."

Penny searched the woods until she found a long stick with a curve at the end. Lying flat on the flagstones at the edge of the pool she prodded for the pin.

"I can touch it all right!" she cried. "I'll pull it over to the side."

"Be careful you don't tumble in," Louise warned, anxiously holding her chum by the waist. "If you should lose your balance--"

Penny hooked the cameo pin in the curve of the stick and began raising it inch by inch up the side of the pool.

"If I can get it up high enough reach down and snatch it," Penny advised her chum. "Oh, shoot, there it goes!"

The pin had slipped away from the stick and settled once more on the bottom of the pool.

"You can't get it, Penny," Louise insisted. "You're making the alligator all excited by prodding around."

"I don't care about _him_. I'll try once more if I can locate the pin. It seems to be hiding from me now."

The water was so disturbed that Penny could not see the pin or the bottom of the pool. She waited several minutes for the dirt to settle and then gazed down once more.

"There it is!" she exclaimed. "It moved over quite a ways to the right."

Louise flattened herself beside Penny. "Oh, let the pin go," she said.

"No, I think I can get it. Say, there seems to be something else on the bottom of the pool."

"Where?"

Penny pointed, and then, as her chum still could not distinguish anything, parted the lily pads with her stick.

"Yes, I do see something now," Louise declared. "What can it be?"

"Doesn't it look like a metal ring?" Penny asked. She had lost all interest in the cameo pin.

"Yes, it does. Someone probably threw it into the pool."

"But it looks to me as if it's attached to the bottom of the tank, embedded in the cement," Penny said. She bent closer to the water, trying to see.

"Be careful," Louise warned nervously. "That alligator might come up and snap off your nose."

Penny paid no heed.

"It is attached!" she announced in an excited voice. "Louise, do you know what I think?"

"What?"

"It's the ring of a trapdoor!"

"A trapdoor!" Louise echoed incredulously.

"You can see for yourself that it's an iron ring."

"It does look a little like one from here," Louise admitted. "But whoever heard of a trapdoor in a lily pool? No one but you would even think of such a thing. It doesn't make sense."

"Does anything on this estate make sense?"

"The ring might have something to do with draining the pool," Louise said without replying to her chum's question. "I suppose a section of the pool could be lifted up and removed. But I'd never call it a trapdoor."

"I wish we could tell for sure what it is." Penny tried to prod the ring with her stick but it was well beyond her reach. "Maybe the alligator has a room down under the pool where he spends his winters!"

"You're simply filled with ideas today," Louise declared. "What about my pin? Shall we let it go?"

Reminded of her original task, Penny set to work once more, trying to draw the cameo to the edge of the tank. She was so deeply engrossed, that she jumped as her chum touched her on the arm.

"Listen, Penny, I think someone is coming!"

From the path at the right they could hear approaching footsteps and the low murmur of voices.

Penny struggled to her feet, dropping the stick.

"We mustn't be caught here," she whispered.

Taking Louise's hand, she drew the girl into the dense bushes directly behind the pool. Scarcely had they secreted themselves when Sylvia Kippenberg and the head gardener came into view. They seated themselves on a rustic bench not far from where the two girls stood.

"I had to talk with you," Sylvia said to the old man. "The police came this morning and asked so many questions. Mother put them off but they'll be back again."

"They didn't learn about the alligator?" the gardener asked gruffly.

"No, they came here but only stayed a few minutes. I don't think they noticed anything wrong."

"Then that's all right."

"Their investigation is only beginning," Sylvia said nervously. "Mother and I both believe it would be wise to get rid of the alligator."

"Wise but not easy," the gardener replied.

"You'll see what you can do about it?"

"Yes. I'll try to get rid of him."

"Then I guess that's all," Sylvia said, but she made no move to leave. She sat staring moodily at the pool.

"Anything else on your mind?" asked the gardener.

"I--I wanted to ask you something, but I scarcely know how."

The gardener waited, watching the girl's face intently.

"You never liked Grant Atherwald," she began nervously.

"Say, what are you driving at?" the man asked quickly. "You're not trying to hint that I had anything to do with Grant Atherwald's disappearance?"

The two faced each other and Sylvia's gaze was the first to fall.

"No, no, of course not," she said.

"I don't know any more about his disappearance than you do," the man told her angrily. "I didn't even see him on the day of the wedding."

"But he came here. The wedding ring was found near the pool. Surely you must have heard some sound for I know you were in this part of the garden."

"Well, I didn't," the man said sullenly. "The only persons I saw were a newspaper photographer and a girl."

"Please don't take offense," Miss Kippenberg murmured, getting up from the bench. "I've been terribly upset these past few days."

She walked slowly to the edge of the pool. There she stopped short, staring down at an object which lay on the flagstones at her feet. It was the stick which Penny had dropped only a moment before.

"What have you found?" the gardener cried.

He went quickly to her side and took the damp stick from her hand.

"Someone has been here prying around," he said in a harsh voice. "This was used to investigate the water in the pool."

"And whoever it was must be close by even now. Otherwise the stick would have dried out in the sun."

"You go back to the house," the man commanded. "I'll look around."

In their hideout amid the bushes, Penny and Louise gazed at each other with chagrin. No word was spoken for even a whisper might have been heard. With a common desire for escape, they glided with cat-like tread toward the river.

CHAPTER 16 _GATHERING CLUES_

The girls could hear no movement behind them as they darted down the path. They dared to hope that they had eluded the old gardener.