CHAPTER XI

  THE WIRELESS DETECTIVE

  Del Mar made his way cautiously along the bank of a little river at themouth of which he left the boat after escaping from the little steamer.

  Quite evidently he was worried by the failure to cut the great Atlanticcable and he was eager to see whether any leak had occurred in theorganization which, as secret foreign agent, he had so carefully builtup in America.

  As he skirted the shore of the river, he came to a falls. Here he movedeven more cautiously than before, looking about to make certain that noone had followed him.

  It was a beautiful sheet of water that tumbled with a roar over theledge of rock, then raced away swiftly to the sea in a cloud of spray.

  Assured that he was alone, he approached a crevice in the rocks, nearthe falls. With another hasty look about, he reached in and pulled alever.

  Instantly a most marvellous change took place, incredible almost beyondbelief. The volume of water that came over the falls actually andrapidly decreased until it almost stopped, dripping slowly in a thinveil. There was the entrance of a cave--literally hidden behind thefalls!

  Del Mar walked in. Inside was the entrance to another, inner cave,higher up in the sheer stone of the wall that the waters had eroded.From the floor to this entrance led a ladder. Del Mar climbed it, thenstopped just inside the entrance to the inner cave. For a moment hepaused. Then he pressed another lever. Almost immediately the thintrickle of water grew until at last the roaring falls completelycovered the cave entrance. It was a clever concealment, contrived bydamming the river above and arranging a new outlet controlled byflood-gates.

  There Del Mar stood, in the inner cave. A man sat at a table, a curiousgear fastened over his head and covering his ears. Before him was ahuge apparatus from which flared a big bluish-green spark, snapping andcrackling above the thunder of the waves. From the apparatus ran wiresapparently up through cables that penetrated the rocky roof of thecavern and the river above.

  It was Del Mar's secret wireless station, close to the hidden submarineharbor which had been established beneath the innocent rocks of thepromontory up the coast. Far overhead, on the cliff over the falls,were the antennae of the wireless.

  "How is she working?" asked Del Mar.

  "Pretty well," answered the man.

  "No interference?" queried Del Mar, adjusting the apparatus.

  The man shook his head in the negative.

  "We must get a quenched spark apparatus," went on Del Mar, pleased thatnothing was wrong here. "This rotary gap affair is out of date. By theway, I want you to be ready to send a message, to be relayed across toour people. I've got to consult the board below in the harbor, first,however. I'll send a messenger to you."

  "Very well, sir," returned the man, saluting as Del Mar went out.

  Out at Fort Dale, Lieutenant Woodward was still entertaining his newfriend, Professor Arnold, and had introduced him to Colonel Swift, thecommanding officer at the Fort.

  They were discussing the strange events of the early morning, when anorderly entered, saluted Colonel Swift and handed him a telegram. TheColonel tore it open and read it, his face growing grave. Then hehanded it to Woodward, who read:

  WASHINGTON, D. C.

  Radio station using illegal wave length in your vicinity. Investigateand report.

  BRANDON,

  Radio Bureau.

  Professor Arnold shook his head slowly, as he handed the telegram back."There's a wireless apparatus of my own on my yacht," he remarkedslowly. "I have an instrument there which I think can help you greatly.Let's see what we can do."

  "All right," nodded Colonel Swift to Woodward. "Try."

  The two went out and a few minutes later, on the shore, jumped intoArnold's fast little motor-boat and sped out across the water untilthey swung around alongside the trim yacht which Arnold was using.

  It was a compact and comfortable little craft with lines that indicatedboth gracefulness and speed. On one of the masts, as they approached,Woodward noticed the wireless aerial. They climbed up the ladder overthe side and made their way directly to the wireless room, where Arnoldsat down and at once began to adjust the apparatus.

  Woodward seemed keenly interested in inspecting the plant which was ofa curious type and not exactly like any that he had seen before.

  "Wireless apparatus," explained Arnold, still at work, "as you know, isdivided into three parts, the source of power, the making and sendingof wireless waves, including the key, spark, condenser and tuning coil,and the receiving apparatus--head telephones, antennae, ground anddetector. This is a very compact system with facilities for a quickchange from one wave length to another. It has a spark gap, quenchedtype, break system relay--operator can hear any interference whiletransmitting--transformation by a single throw of a six-point switchwhich tunes the oscillating and open circuits to resonance."

  Woodward watched him keenly, following his explanation carefully, asArnold concluded.

  "You might call it a radio detective," he added.

  Even the startling experience of the morning when she was carried offand finally jumped from the little tramp steamer that had attempted tocut the cable did not dampen Elaine's ardor. She missed the guidinghand of Kennedy, yet felt impelled to follow up and investigate thestrange things that had been happening in the neighborhood of hersummer home since his disappearance.

  I succeeded in getting her safely home after Burnside and I rescued herin the hydroaeroplane, but no sooner had she changed her clothes fordry ones than she disappeared herself. At least I could not find her,though, later, I found that she had stolen away to town and there hadpurchased a complete outfit of men's clothes from a second hand dealer.

  Cautiously, with the large bundle under her arm, she returned to DodgeHall and almost sneaked into her own home and up-stairs to her room.She locked the door and hastily unwrapped the bundle taking out atattered suit and the other things, holding them up and laughinggleefully as she took off her own pretty clothes and donned thesehideous garments.

  Quickly she completed her change of costume and outward character. Asshe surveyed herself in the dainty mirror of her dressing-table shelaughed again at the incongruity of her pretty boudoir and the roughmen's clothes she was wearing. Deftly she arranged her hair so that herhat would cover it. She picked a black mustache from the table andstuck it on her soft upper lip. It tickled and she made a wry face overit. Then she hunted up a cigarette from the bundle which she hadbrought in, lighted it and stuck it in the corner of her mouth, lettingit droop jauntily. It made her cough tremendously and she threw it away.

  Finally she went to the door and down-stairs. No one was about. Sheopened the door and gazed around. All was quiet. It was a new role forher, but, with a bold front, she went out and passed down to the gateof the grounds, pulling her hat down over her eyes and assuming a toughswagger.

  Only a few minutes before, down in the submarine harbor, the officersof the board of foreign agents had been grouped about Del Mar, who hadentered and taken his place at their head, very angry over the failureto cut the cable. As they concluded their hasty conference, he wrote amessage on a slip of paper.

  "Take this to our wireless station," he ordered, handing it to one ofthe men.

  The man took it, rose, and went to a wardrobe from which he extractedone of the submarine suits. With the message in his hand, he went outof the room, buckling on the suit.

  A few minutes later the messenger in the submarine suit bobbed up outof the water, near the promontory, and climbed slowly over the rockstoward a crevice, where he began to take off the diving outfit.

  Having finished, he hid the suit among the rocks and then went along tothe little river, carefully skirting its banks into the ravine in whichwere the falls and the wireless cave.

  In her disguise, Elaine had made her way by a sort of instinct alongthe shore to the rocky promontory where we had discovered the messagein the tin tube in the water.

  Something, she knew not what, w
as going on about there, and shereasoned that it was not all over yet. She was right. As she lookedabout keenly she did see something, and she hid among the rocks. It wasa man, all dripping, in an outlandish helmet and suit.

  She saw him slink into a crevice and take off the suit, then, as hemoved toward the river ravine, she stole up after him.

  Suddenly she stopped stark still, surprised, and stared.

  The man had actually gone up to the very waterfall. He had pressed whatlooked like a lever and the water over the falls seemed to stop. Thenhe walked directly through into a cave.

  In the greatest wonder, Elaine crept along toward the falls. Inside thecave Del Mar's emissary started to climb a ladder to an inner cave. Ashe reached the top, he glanced out and saw Elaine by the entrance. Withan oath he jumped into the inner entrance. His hand reached eagerly fora lever in the rocks and as he found and held it, he peered outcarefully.

  Elaine cautiously came from behind a rock where she had hidden herselfand seeing no one apparently watching, now, advanced until she stooddirectly under the trickle of water which had once been the falls. Shegazed into the cave, curiously uncertain whether she dared to go inalone or not.

  The emissary jerked fiercely at the lever as he saw Elaine.

  Above the falls a dam had been built and by a system of levers thegates could be operated so that the water could be thrown over thefalls or diverted away, at will. As the man pressed the lever, theflood gates worked quickly.

  Elaine stood gazing eagerly into the blackness of the cave. Just then agreat volume of water from above crashed down on her, with almostcrushing weight.

  How she lived through it she never knew. But, fortunately, she had notgone quite far enough to get the full force of the water. Still, theterrific flood easily overcame her.

  She was swept, screaming, down the stream.

  . . . . . . .

  Rather alarmed at the strange disappearance of Elaine after I broughther home, I had started out along the road to the shore to look forher, thinking that she might perhaps have returned there.

  As I walked along a young tough--at least at the time I thought it wasa young tough, so good was the disguise she had assumed and so well didshe carry it off--slouched past me.

  What such a character could be doing in the neighborhood I could notsee. But he was so noticeably tough that I turned and looked. He kepthis eyes averted as if afraid of being recognized.

  "Great Caesar," I muttered to myself, "that's a roughneck. This placeis sure getting to be a hang-out for gunmen."

  I shrugged my shoulders and continued my walk. It was no business ofmine. Finding no trace of Elaine, I returned to the house. AuntJosephine was in the library, alone.

  "Where's Elaine?" I asked anxiously.

  "I don't know," she replied. "I don't think she's at home."

  "Well, I can't find her anywhere," I frowned wandering out at a losswhat to do, and thrusting my hands deep in my pockets as an aid tothought.

  Somehow, I felt, I didn't seem to get on well as a detective withoutKennedy. Yet, so far, a kind providence seemed to have watched over us.Was it because we were children--or--I rejected that alternative.

  Walking along leisurely I made my way down to the shore. At a bridgethat crossed a rather turbulent stream as it tumbled its way toward thesea, I paused and looked at the water reflectively.

  Suddenly my vagrant interest was aroused. Up the stream I saw some onestruggling in the water and shouting for help as the current carriedher along, screaming.

  It was Elaine. The hat and mustache of her disguise were gone and herbeautiful Titian hair was spread out on the water as it carried her nowthis way, now that, while she struck out with all her strength to keepafloat. I did not stop to think how or why she was there. I swung overthe bridge rail, stripping off my coat, ready to dive. On she came withthe swift current to the bridge. As she approached I dived. It was nota minute too soon. In her struggles she had become thoroughlyexhausted. She was a good swimmer but the fight with nature was unequal.

  I reached her in a second or so and took her hand. Half pulling, halfshoving her, I struck out for the shore. We managed to make it togetherwhere the current was not quite so strong and climbed safely up a rock.

  Elaine sank down, choking and gasping, not unconscious but pretty muchall in and exhausted. I looked at her in amazement. She was the toughcharacter I had just seen.

  "Why, where in the world did you get those togs?" I queried.

  "Never mind my clothes, Walter," she gasped. "Take me home for some dryones. I have a clue."

  She rose, determined to shake off the effects of her recent plunge andwent toward the house. As I helped her she related breathlessly whatshe has just seen.

  Meanwhile, back of that wall of water, the wireless operator in thecave was sending the messages which Del Mar's emissary dictated to him,one after another.

  . . . . . . .

  With the high resistance receiving apparatus over his head, Arnold waslistening to the wireless signals that came over his "radio detective"on the yacht, moving the slider back and forth on a sort of tuningcoil, as he listened. Woodward stood close beside him.

  "As you know," Arnold remarked, "by the use of an aerial, messages maybe easily received from any number of stations. Laws, rules, andregulations may be adopted by the government to shut out interlopersand to plug busybody ears, but the greater part of whatever istransmitted by the Hertzian waves can be snatched down by this wirelessdetective of mine. Here I can sit in my wireless room with thisear-phone clamped over my head drinking in news, plucking the secretsof others from the sky--in other words, this is eavesdropping by awireless wire-tapper."

  "Are you getting anything now?" asked Woodward.

  Arnold nodded, as he seized a pencil and started to write. Thelieutenant bent forward in tense interest. Finally Arnold read what hehad written and with a peculiar, quiet smile handed it over. Woodwardread. It was a senseless jumble of dots and dashes of the Morse codebut, although he was familiar with the code, he could make nothing outof it.

  "It's the Morse code all right," he said, handing it back with apuzzled look, "but it doesn't make any sense."

  Arnold smiled again, took the paper, and without a word wrote on itsome more. Then he handed it back to Woodward. "An old trick," he said."Reverse the dots and dashes and see what you get."

  Woodward looked at it, as Arnold had reversed it and his face lightedup.

  "Harbor successfully mined," he quoted in surprise.

  "I'll show you another thing about this radio detective of mine," wenton Arnold energetically. "It's not only a wave length measurer, but bya process of my own I can determine approximately the distance betweenthe sending and the receiving points of a message."

  He attached another, smaller machine to the wireless detector. In theface was a moving finger which swung over a dial marked off in milesfrom one upward. As Arnold adjusted the new detector, the hand began tomove slowly. Woodward looked eagerly. It did not move far, but came torest above the figure "2."

  "Not so very far away, you see, Lieutenant," remarked Arnold, pointingat the dial face.

  He seized his glass and hurried to the deck, levelling it at the shore,leaning far over the rail in his eagerness. As he swept the shore, hestopped suddenly. There was a house-roof among the trees with awireless aerial fastened to the chimney, but not quite concealed by thedense foliage.

  "Look," he cried to Woodward, with an exclamation of satisfaction,handing over the glass.

  Woodward looked. "A secret wireless station, all right," he agreed,lowering the glass after a long look.

  "We'd better get over there right away," planned Arnold, leading theway to the ladder over the side of the yacht and calling to the sailorwho had managed the little motor-boat to follow him.

  Quickly they skimmed across to the shore. "I think we'd better send tothe Fort for some men," considered Arnold as they
landed. "We may needreinforcements before we get through."

  Woodward nodded and Arnold hastily wrote a note on a rather large scrapof paper which he happened to have in his pocket.

  "Take this to Colonel Swift at Fort Dale," he directed the sailor. "Andhurry!"

  The sailor loped off, half on a run, as Arnold and Woodward left downthe shore, proceeding carefully.

  At top speed, Arnold's sailor made his way to Fort Dale and wasdirected by the sentry to Colonel Swift who was standing before theheadquarters with several officers.

  "A message from Lieutenant Woodward and Professor Arnold," heannounced, approaching the commanding officer and handing him the note.Colonel Swift tore it open and read:

  Have located radio aerial in the woods along shore. Please send squadof men with bearer.--ARNOLD.

  "You just left them?" queried the Colonel.

  "Yes sir," replied the sailor. "We came ashore in his boat. I don'tknow exactly where they went but I know the direction and we can catchup with them easily if we hurry, sir."

  The colonel handed the note quickly to a cavalry officer beside him whoread it, saluted at the orders that followed, turned and strode off,hastily stuffing the paper in his belt, as the sailor went, too.

  Meanwhile, Del Mar's valet was leaving the bungalow and walking downthe road on an errand for his master. Up the road he heard the clatterof hoofs. He stepped back off the road and from his covert he could seea squad of cavalry headed by the captain and a sailor cantering past.

  The captain turned in the saddle to speak to the sailor, who rode likea horse marine, and as he did so, the turning of his body loosened apaper which he had stuffed quickly into his belt. It fell to theground. In their hurry the troop, close behind, rode over it. But itdid not escape the quick eye of Del Mar's valet.

  They had scarcely disappeared around a bend in the road when he steppedout and pounced on the paper, reading it eagerly. Every line of hisface showed fear as he turned and ran back to the bungalow.

  "See what I found," he cried breathlessly bursting in on Del Mar whowas seated at his desk, having returned from the harbor.

  Del Mar read it with a scowl of fury. Then he seized his hat, and ashort hunter's axe, and disappeared through the panel into thesubterranean passage which took him by the shortest cut through thevery hill to the shore.

  Slowly Arnold and Woodward made their way along the shore, carefullysearching for the spot where they had seen the house with the aerial.At last they came to a place where they could see the deserted house,far up on the side of a ravine above a river and a waterfalls. Theydived into the thick underbrush for cover and went up the hill.

  Some distance off from the house, they parted the bushes and gazed offacross an open space at the ramshackle building. As they looked theycould see a man hurry across from the opposite direction and into thehouse.

  "As I live, I think that's Del Mar," muttered Arnold.

  Woodward nodded, doubtfully, though.

  In the house, Del Mar hurried to a wall where he found and pressed aconcealed spring. A small cabinet in the plaster opened and he took outa little telephone which he rang and through which he spoke hastily."Pull in the wires," he shouted. "We're discovered, I think."

  Down in the wireless station in the cave, the operator at hisinstrument heard the signal of the telephone and quickly answered it."All right, sir," he returned with a look of great excitement andanxiety. "Cut the wires and I'll pull them in."

  Putting back the telephone, Del Mar ran to the window and looked outbetween the broken slats of the closed blinds. "Confound them!" hemuttered angrily.

  He could see Arnold and Woodward cautiously approaching. A moment laterhe stepped back and pulled a silk mask over his upper face, leavingonly his eyes visible. Then he seized his hunter's axe and dashed upthe stairs. Through the scuttle of the roof he came, making his wayover to the chimney to which the wireless antennae were fastened.

  Hastily he cut the wires which ran through the roof from the aerial. Ashe did so he saw them disappear through the roof. Below, in the cave,down in the ravine back of the falls, the operator was hastily haulingin the wire Del Mar had cut.

  Viciously next, Del Mar fell upon the wooden aerial itself, chopping itright and left with powerful blows. He broke it off and threw it overthe roof.

  Below, Arnold and Woodward, taking advantage of every tree and shrubfor concealment, had almost reached the house when the broken aerialfell with a bang almost on them. In surprise they dropped back of atree and looked up. But from their position they could see nothing.Together they drew their guns and advanced more cautiously at the house.

  Del Mar made his way back quickly over the roof, back through thescuttle and down the stairs again. Should he go out? He looked out ofthe window. Then he went to the door. An instant he paused thinking andlistening, his axe raised, ready for a blow.

  Arnold and Woodward, by this time, had reached the door which swungopen on its rusty hinges. Woodward was about to go in when he felt ahand on his arm.

  "Wait," cautioned Arnold. He took off his hat and jammed it on the endof a stick. Slowly he shoved the door open, then thrust the hat andstick just a fraction of a foot forward.

  Del Mar, waiting, alert, saw the door open and a hat. He struck at ithard with the axe and merely the hat and stick fell to the floor.

  "Now, come on," shouted Arnold to Woodward.

  In the other hand, Del Mar held a chair. As Woodward dashed in withArnold beside him, Del Mar shied the chair at their feet. Woodward fellover it in a heap and as he did so the delay was all that Del Mar hadhoped to gain. Without a second's hesitation he dived through an openwindow, just as Arnold ran forward, avoiding Woodward and the chair. Itwas spectacular, but it worked. Arnold fired, but even that was notquick enough. He turned and with Woodward who had picked himself up inspite of his barked shins and they ran back through the door by whichthey had entered.

  Recovering himself, Del Mar dashed for the woods just as Arnold andWoodward ran around the side of the house, still blazing away afterhim, as they followed, rapidly gaining.

  Elaine changed her clothes quickly. Meanwhile she had ordered horsesfor both of us and a groom brought them around from the stables. Ittook me only a short time to jump into some dry things and I waitedimpatiently.

  She was ready very soon, however, and we mounted and cantered off,again in the direction of the shore where she had seen the remarkablewaterfall, of which she had told me.

  We had not gone far when we heard sounds, as if an army were bearingdown on us. "What's that?" I asked.

  Elaine turned and looked. It was a squad of cavalry.

  "Why, it's Lieutenant Woodward's friend, Captain Price," she exclaimed,waving to the captain at the head of the squad.

  A moment later Captain Price pulled up and bowed. Quickly we told himof what Elaine had just discovered.

  "That's strange," he said. "This man--" indicating the sailor--"hasjust told me that Lieutenant Woodward and Professor Arnold areinvestigating a wireless outfit over near there. Perhaps there's someconnection."

  "May we join you?" she asked.

  "By all means," he returned. "I was about to suggest it myself."

  We fell in behind with the rest and were off again.

  Under the direction of the sailor we came at last to the ravine wherewe looked about searchingly for some trace of Arnold and Woodward.

  "What's that noise?" exclaimed one of the cavalrymen.

  We could hear shots, above us.

  "They may need us," cried Elaine, impatiently.

  It was impossible to ride up the sheer height above.

  "Dismount," ordered Captain Price.

  His men jumped down and we followed him. Elaine struggled up, nowhelped by me, now helping me.

  Further down the hill from the deserted house which we could see aboveus at the top was an underground passage which had been built to divertpart of the water above the falls for power. Through it the watersurged and over this boiling
stream ran a board walk, the length of thetunnel.

  Into this tunnel we could see that a masked man had made his way. As hedid so, he turned for just a moment and fired a volley of shots.

  Elaine screamed. There were Arnold and Woodward, his targets, coming onboldly, as yet unhit. They rushed in after him, in spite of his runningfire, returning his shots and darting toward the tunnel entrancethrough which he still blazed back at them.

  From our end of the ravine, we could see precisely what was going on."Come--the other end of the tunnel," shouted Price, who had evidentlybeen over the ground and knew it.

  We made our way quickly to it and it seemed as if we had our mantrapped, like a rat in a hole.

  In the tunnel the man was firing back at his pursuers as he ran alongthe board walk for our end. He looked up just in time as he approachedus. There he could see Price and his cavalry waiting, cutting offretreat. We were too many for him. He turned and took a step back.There were Arnold and Woodward with levelled guns peering in as thoughthey could not see very clearly. In a moment their eyes would becomeaccustomed as his to the darkness. What should he do? There was not asecond to waste. He looked down at the planks beneath him and the blackwater slipping past on its way to the power station. It was a desperatechance. But it was all that was left. He dropped down and let himselfwithout even a splash into the water.

  Arnold and Woodward took a step into the darkness, scarcely knowingwhat to expect, their eyes a bit better accustomed to the dusk. But ifthey had been there an hour, in all probability they could not haveseen what was at their very feet.

  Del Mar had sunk and was swimming under water in the swift blackcurrent sweeping under them. As they entered, he passed out, nerved upto desperation.

  Down the stream, just before it took its final plunge to the powerwheel, Del Mar managed by a superhuman effort to reach out and grasp awooden support of the flooring again and pull himself out of thestream. Smiling grimly to himself, he hurried up the bank.

  "Some one's coming," whispered Price. "Get ready."

  We levelled our guns. I was about to fire.

  "Look out! Don't shoot!" warned a voice sharply. It was Elaine. Herkeen eyes and quick perception had recognized Arnold, leading Woodward.We lowered our guns.

  "Did you see a man, masked, come out here?" cried Woodward.

  "No--he must have gone your way," we called.

  "No, he couldn't."

  Arnold was eagerly questioning the captain as Elaine and I approached."Dropped into the water--risked almost certain death," he muttered,half turning and seeing us.

  "I want to congratulate you on your nerve for going in there," beganElaine, advancing toward the professor.

  Apparently he neither heard nor saw us, for he turned as soon as he hadfinished with Price and went into the cave as though he were too busyto pay any attention to anything else.

  Elaine looked up at me, in blank astonishment.

  "What an impolite man," she murmured, gazing at the figure all stoopedover as it disappeared in the darkness of the tunnel.