the moon rode high in the heavens as the cabin cruiser let go its anchor in a cove off the kippenberg estate. penny who had been dozing for the past hour in her self-imposed prison started up in alarm as jerry nudged her in the ribs.

“wake up,” he whispered. “we’re here.”

“at the estate?”

“i think so.”

on the deck above their heads they could hear the men talking together.

“you’ll come along with us, atherwald,” aaron dietz said. “flora, you stay here and guard the boat. if you see anyone watching or acting suspiciously, blow the whistle two short blasts.”

“i don’t want to stay here alone,” the girl whimpered. “i’m afraid.”

“you’ll do as i say,” the man ordered harshly. “get started, gus. it’s two o’clock now. we won’t have many hours before daylight.”

[193]

in making her plans penny had not once considered that the men might leave a guard on the cruiser. with the girl posted as a lookout they were still prisoners in the cabin.

“we have to get out of here now or never,” she whispered. “what shall we do about flora?”

“we’ll rush her and take a chance on the whistle.”

they slipped out of their hiding place and crawled noiselessly up the steep stairway. pausing there, they watched the shadowy figure of the girl in the bow of the boat. she was quite alone, for her companions had disappeared into the woods.

“now!” commanded jerry in a whisper.

with a quick rush he and penny were across the deck. they approached flora from behind and were upon her before she could turn her head. jerry grasped her arms while penny clapped a hand over her mouth to prevent a scream. although the girl fought fiercely, she was no match for two persons.

stripping off her sash, penny gave it to jerry to use as a gag. they bound the girl’s wrists and ankles, then carried her down into the cabin.

“i hate to leave her like that,” said penny as they went back on deck.

“don’t waste your sympathy,” replied jerry. “she doesn’t deserve it. anyway, we’ll soon set her free. we must bring the police now.”

“the nearest house with a telephone is about a half mile away.”

[194]

“it won’t take us long to cover the distance,” jerry said, helping her down from the boat.

“you go alone,” urged penny. “i’ll stay here and keep watch.”

“i don’t like to leave you.”

“go on.” penny gave him a little push. “and hurry!”

after jerry had reluctantly left, she plunged into the trees, carefully picking her way along the path which led to the lily pool. a short distance brought her to the clearing. halting, she saw the three men and grant atherwald silhouetted in the bright moonlight. the latter was still handcuffed, guarded by aaron dietz who allowed his companions to do the hard labor.

gus and jake had broken open the door of the stone tower. the soft purr of a motor told penny that they had started draining the pool. she wondered what the men would do when they discovered that the tank contained a very live alligator.

“it ought to put a crimp in their work,” she chuckled. “mr. kippenberg couldn’t have chosen a more effective guard for his gold.”

but gradually as the pool drained lower and lower, it struck penny as odd that the men did not notice the alligator. belatedly, it occurred to her that the kippenberg gardener had probably succeeded in getting rid of the monster since her visit to the garden earlier in the day.

[195]

“something like that would happen,” she thought. “oh, well, even so jerry ought to get here with the police in ample time.”

only the waning of the moon gave indication of how swiftly the night was passing. penny became alarmed as she observed how fast the pool emptied. jerry would not have as long as she had anticipated. but surely, he would bring help before it was too late.

presently, one of the men shut off the motor in the stone tower, saying with quiet jubilance:

“there, she’s empty!”

he jumped down into the tank, and almost at once uttered a cry of discovery.

“here it is, just as he said! the ring to the trap! give us some help, gus.”

with aaron dietz and the bewildered bridegroom watching from above, the two men raised the heavy block of cement. penny drew closer for she did not wish to miss anything. she stood in the shadow of a tree scarcely fifteen yards from where the men worked.

“a stairway leads down into an underground vault!” jake cried exultantly. “we’ve found the hiding place of the gold.”

[196]

“toss me your flashlight, aaron,” called gus. “we’ll soon have all of the treasure out of here.”

the next ten minutes brought a confused whirl of impressions. penny’s thoughts were in turmoil. why didn’t jerry come with the police? as soon as the men carried the burden of gold to the boat they would discover flora, bound and gagged. then they would suspect that a trap had been laid. oh, why didn’t jerry hurry?

gus and jake had descended into the underground vault. as the light reappeared, penny was dumbfounded to see that the men were empty handed.

“nothing down there,” gus reported in disgust. “nothing!”

“then we’ve been tricked!” aaron dietz turned furiously upon his prisoner. “you’ll pay for this!”

“i thought the gold was here,” answered grant atherwald.

“lock him up in the vault and start the water running,” advised jake harshly. “it’s a good way to be rid of him.”

the suggestion appealed to aaron dietz. at a nod from him, atherwald was seized and dragged down into the pool. he was shoved into the vault, but before the two men could lower the heavy cement block into place, a signal from dietz arrested their action.

“wait!”

[197]

in her anxiety over grant atherwald, penny had moved closer to the pool. without realizing that she was exposing herself, she stood so that her shadow fell clearly across the open space. before she comprehended her danger, dietz hurled himself upon her, seizing her roughly by the arms.

penny struggled to free herself but could not. the man’s grip was like steel.

“so you were spying!” he exclaimed harshly.

“i—i was just watching,” penny stammered. “don’t you remember me? i am the girl who pulled you out of the river when your car went over the drawbridge.”

the man looked closely at her, and for an instant she dared hope that he would recall her with gratitude. but his face hardened again and he said unfeelingly:

“you know entirely too much, my little girl. this is one story you will never write for your father’s paper. your curiosity has proven your undoing. you share the fate of your very good friend.”

with a sinking heart penny realized by the man’s words that he knew her to be the daughter of a newspaper publisher, and that he had guessed her part in the trick played upon him.

“down you go!” dietz said harshly.

[198]

as he dragged her toward the pool, penny screamed at the top of her lungs. a hand was clapped over her mouth. she bit it savagely, but her efforts to free herself were of no avail.

the men shoved her headlong down the stone stairway into the pit.

“now scream as much as you like,” aaron dietz hurled after her. “no one will hear you.”

the heavy stone slab dropped into place.

penny picked herself up from the steps. terror gripped her, and with a sob she called frantically:

“mr. atherwald! mr. atherwald!”

“here at the bottom of the steps,” he answered with a groan.

“are you hurt?”

“only bruised. but my hands are still in cuffs.”

penny limped down the stairway and helped the man to his feet.

“we’re done for now,” he said. “no one will ever look for us down in this vault. and our cries will never be heard.”

“don’t give up,” penny murmured encouragingly. “we may be able to lift the stone. come let’s try.”

mounting the stairs, they applied their shoulders to the massive door, but their best efforts did not raise it an inch.

“listen!” cried atherwald suddenly.

they both could hear the sound of water running into the empty pool.

[199]

“in an hour’s time no one will ever guess that a hidden vault lies beneath the tank!” atherwald groaned. “we’re doomed!”

“if we can hear the water splashing above us, our voices might carry!” penny reasoned. “let’s cry out for help. now, together!”

they shouted over and over until their voices failed them. then, completely discouraged, they sagged down on the stairway to rest.

“nothing went as i planned,” penny said dismally. “i really thought the gold was hidden in this vault. if the men had found it, they would have spent hours removing the loot to their boat. jerry would have come with the police and everything would have been all right.”

grant atherwald was not listening to the girl’s words. he struggled to his feet, pressing his ear against the trapdoor.

“the water has stopped running!”

“are you sure?” penny sprang up and stood beside him, listening.

“yes, and i hear voices!”

with one accord, they shouted for help. could it be imagination or did they hear an answering cry? as they repeated their frantic call, there was a scraping on the stone above their heads.

“stand away,” ordered a muffled voice.

[200]

before penny and the bridegroom could obey, the great door lifted. a deluge of water poured in, its force nearly washing them from the steps. but in another moment the passage was clear and they stumbled up through the rectangular opening.

jerry grasped penny’s hand, helping her out of the vault. one of the blue-coated policemen aided atherwald, unfastening the handcuffs which held him a prisoner.

“you’re all right, penny?” the reporter asked anxiously.

“i—i feel like a drowned rat,” she laughed, shaking water out of her hair. then, with a quick change of mood she asked: “did you get aaron dietz and his men?”

“no,” jerry answered in disgust. “when we crossed the river five minutes ago, the cruiser was still there. no sign of anyone around. i brought the police here, and now i suppose they’ve made their get-away.”

“oh, jerry, we can’t let them escape! send the police—”

“now don’t get worked up,” the reporter soothed. “a squad started back just as soon as we found out what had happened here.”

“dietz and his men must have seen the police crossing the river,” speculated penny. “they may have hidden in the bushes, biding their time. by now they’ve slipped away in their boat.”

“i’m afraid of it,” jerry admitted. “i traveled as fast as i could.”

[201]

as one of the policemen lifted penny out of the pool, a noise which sounded like the back-firing of an automobile, broke the stillness of the night. it was followed by a volley of similar sounds.

“gunfire!” exclaimed penny.

the policemen started at a run through the woods toward the place where the white cruiser had last been seen. penny hesitated, and then took the opposite direction, coming out of the woods at a point directly opposite the drawbridge.

gazing far up the river she could see the white cruiser, flashes of fire coming from the cabin window as the desperadoes exchanged shots with the police, who were concealed in the woods.

“that boat will try to run for it in another minute,” penny thought. “if only the drawbridge were down!”

kicking off her shoes, she dived into the water, swimming diagonally across the river to take advantage of the swift current. her powerful strokes brought her to shallow water and she waded ashore through ankle-deep mud. as she scrambled up the slippery bank, her wet clothing plastered to her body, she heard the roar of the cruiser’s motor.

“they’ve started the engine!” she thought. “in another minute the boat will be at the bridge. hurry! hurry!”

[202]

penny could force herself to no greater effort. breathless, she reached the gearhouse and groped frantically under the door. had thorny failed to hide the key there? no, her fingers seized upon it.

trembling with excitement, she turned it in the lock. the door of the gearhouse swung open. now could she remember how to lower the bridge? any mistake would be costly, for by this time she could hear the cruiser racing down the river at full speed. if only it were light enough so that she could see the gears!

she pulled a lever and her heart leaped as the motor responded with a pleasant purr. the power was on!

“now to lower the bridge!” thought penny. “but which lever is the right one? i’m not sure.”

with a prayer in her heart she grasped the one closest at hand and eased it forward. there was a grinding of gears as the tall cantilevers began to move. they were coming down, but oh, so slowly!

“hurry! hurry! hurry!” penny whispered, as if her words could speed the bridge on its journey.

the white cruiser drove onward at full speed. lower came the bridge. penny held her breath, knowing it would be a matter of inches whether or not the boat would clear. the man at the wheel, aware of the danger, did not swerve from his course.

the bridge settled into place. as the crash came, penny closed her eyes.

“i did it! i’ve stopped them!” she thought, and sagged weakly against the gear house.