"The Barracuda could still lurk among those lower channels," reminded The Shadow. "There is something about the grotto, though, that should interest us. It is a place where Sergon and his crew can go ash.o.r.e."

"To what purpose?"

"To unload their swag, as they have probably already done. To leave extra men who may be wounded, or unneeded on an expedition. A place, too, to keep prisoners-your men, commander, who were captured with the Barracuda."

An idea struck Prew.

"If we could lure the Barracuda out! Without the swag, without the prisoners! While someone remained here, and the Lamprey lurked below! It would mean -"

Prew stopped, realizing that The Shadow was ahead on every point. With a slight smile, The Shadow added in Cranston's quiet tone: "It would mean, moreover, that by this time the Barracuda would find a fleet surrounding Marac.o.o.n Reef. Ships prepared to welcome her, ready to give proper chase, since they have learned the speed of which a Z-boat is capable."

There was a nod from Prew, but his face showed doubt. He could not figure just what lure would bring the Barracuda from her lair. Wild schemes flashed to his mind; all were preposterous. Then he heard the steady voice of Cranston.

Step by step, The Shadow was detailing a method by which the deed could be accomplished. It meant that Prew would remain aboard the Lamprey with his entire crew, for only one person would have to be landed in the grotto.

That one venturer would be The Shadow.

SETTLING a few fathoms deeper, the Lamprey worked forward. By the time Prew was inching her upward, The Shadow was in the circular conning tower. He signaled to Salvo.

The cylindrical wall raised, the cap above unclamped.

Squeezing out, The Shadow stretched his hands to a line of rivets. Dragging his legs in the water, he worked his way to the rounded surface of the other ship.

Waiting there, he watched the cap clamp tight above the conning tower of the Lamprey.

Allowing for a proper time interval, Salvo had pulled the lever. The Lamprey went from sight.

Glow was very slight above the water level. Moving carefully along the sloping side of the Barracuda, The Shadow reached a runway. He could hear voices coming from a ledge among the rocks; he saw the glow of flashlights. But they were going in the opposite direction, into caverns above the water line.

Then darkness. The Shadow was about to follow the runway to the sh.o.r.e, when a light came moving back toward him. Only a few feet distant was the wide conning tower of the Barracuda, its half dome open. Calculating that the inner cylinder would be lowered, he dropped aboard.

Down the spiral stairway, The Shadow started toward the control room. He met the circularbulkhead, much wider in diameter than the one on the Lamprey. Rounding it, he saw that the door of the control room was open. Drunken voices came from there.

Across the way was a storeroom, so filled with junk that no one could have squeezed inside it. Everything from old clothes to parts of torpedoes had been piled there. The pa.s.sage, however, was dark enough. Hearing footsteps from the stairway, The Shadow waited where he was.

Into the dim light came Claudette Marchand.

The girl stooped to open the hidden panel to communicate with Commander Prew. Silently, The Shadow drew close behind her. He watched while she made contact, saw the blinks of the message that came promptly from Prew.

A gasp left Claudette's lips. In that message, she was learning facts that pertained to The Shadow. She remembered the battler at the boathouse. Perhaps it was such recollection that caused her to stare up suddenly from the floor.

Claudette saw The Shadow.

She knew who he must be, although he was no longer a being clad in black. Instead, she saw a man, Lamont Cranston, whose features were strangely masklike. His face, though disguised, was the sort that she had pictured as belonging to The Shadow. That, however, was probably because of its expression, rather than its mold.

FROM that moment, Claudette Marchand realized that she would have needed no instructions to make her trust The Shadow. She had been too tense when she had met him at the boathouse.

Claudette had been through many perils since then, had used her wits so often that they were remarkably sharpened.

As The Shadow supposed, Claudette had gotten the full confidence of Sergon and his crew.

She had done that by revealing facts about the Barracuda that they would have learned anyway.

With a final whisper, The Shadow went up the spiral stairs. Claudette waited, counting off the minutes. After five of them, she was to follow. Her duty was to talk to Sergon, to suggest a further search of the Barracuda, in hope of finding concealed equipment.

She was sure that she could manage that game; but even if the bluff weakened, The Shadow would be near. Claudette gave a satisfied smile as she reached down to close the stairway panel. Her five minutes were ended.

So were her hopes, as a harsh chuckle made her turn. Staring from the spiral steps was the very man that she intended to trick. His face hard and evil, Felix Sergon gave a sneer that marked an end to all his trust.

Claudette was trapped, caught in a secret task; and The Shadow was no longer standing by!

CHAPTER XIX. CRIME'S LAST STROKE.

CLAMPING a big hand on Claudette's arm, Sergon spun the girl away from the open panel.

He studied the bright light that he saw there, then snapped the question: "What's this for?"

"I don't know." Claudette tried to make the lie sound truthful. "I just discovered it by accident."

She could have added that Sergon would soon have "discovered" the panel himself; for her move, as detailed by The Shadow, was to suggest a search that would have eventually uncovered the subsea wireless device.

Such a result would have brought her commendation, and with it, the only privilege she intended to ask: that of remaining ash.o.r.e. But present circ.u.mstances eliminated all such prospects.

Sergon was working on the light, uns.c.r.e.w.i.n.g it, tightening it again. That action, Claudette knew, would be noted aboard the Lamprey. She began to talk fast.

"I had a suggestion," she began. "I thought it would be wise to search this ship, just on the chance that we would find something new. I came aboard to talk to you -"

Sergon's interrupting laugh was raspy. He was positive that Claudette knew he was on sh.o.r.e. The excuse was to him another proof that Claudette had double-crossed him.

The light from below the steps began to blink.

"Attention," it said, in Morse. "This is Commander Rodney Prew. I offer a reward to any loyal man. Attention -"

Sergon released Claudette's arm. He backed her to a corner by brandishing a gun. The signal was flashing its previous announcement. Sergon snorted.

"Any loyal man," he sneered. "He's thinking of you! He says 'man' so we won't suspect. But he knows you're for him. Lucky you didn't find this thing before."

That last remark was Claudette's one glimpse of hope. She was granting her own death as a certainty; but she saw a chance that might at least bring success to the all-important cause. Sergon had seen through her loyalty, but he did not realize its past importance. He was taking the very bait that The Shadow had prepared.

There was a switch just below the blinking bulb. Sergon began to tap it. The light flashed a question: "Who are you?"

Sergon gave a deep, ugly chuckle, as he tapped back: "Claudette Marchand. I am loyal. State how I can aid."

Eyeing Claudette, Sergon observed that she had read the coded taps. It pleased him to think how cleverly he had seized upon her name as the one that Prew hoped to hear.

A longer message came from Prew. In it, the commander stated that he was aboard another ship, the Lamprey, a Z-boat like the Barracuda. From the way Prew put it, Sergon was sure that Claudette had never heard of the other ship before. As he looked toward the girl, she feigned a surprised expression and managed it to perfection.

"We are near Marac.o.o.n Reef," stated the light, in conclusion. "State how we can reach you."

Sergon stroked his chin. He was scheming something, and Claudette hoped that his ingenious brain would jump to the very idea that The Shadow wanted him to hold. At last, Sergon tapped. Again, he had taken the bait!

"State your position," he ordered. "I can then inform you later."

Prew's blinks located the Lamprey as two miles east of Marac.o.o.n Reef. Sergon signed off.

He kicked the panel shut. With the gun, he forced Claudette toward the control room.

"You'll see what we'll do to Prew," he told her. "So he's got another Z-boat? He won't have, very long!"

THE drunks in the control room came to their feet when Sergon arrived there. He shoved Claudette toward them, told them to keep her under guard.

"Ash.o.r.e?" asked one man, thickly. "With the rest of 'em?"

"No. On board," retorted Sergon. "She's going to see the fun. She'd better enjoy it"-he slanted a look at Claudette-"because it's the last fun she'll have!"

Stamping out to the pa.s.sage, Sergon bellowed orders. By the end of ten minutes, all was ready. Her conning tower closed, the Barracuda began to sink under the grotto.

Sergon knew the pa.s.sages beneath the rocks; he avoided blind channels that had troubled the Lamprey. As they came out into the open sea, he began to sight through the periscope.

He had kept Claudette in the control room; his remarks were for her benefit.

"We'll fix that fool Prew," he growled. "Likely enough, he'll have his ship up on the surface, because he won't know we're coming."

He paused as he viewed the surface through the periscope. His hands gripped the controls.

With a swift oath, Sergon fixed the levers. He turned about, not merely to address Claudette but all the others present. At first, his face showed anger; then over it spread a knowing leer.

"That Z-boat talk sounded phony," he declared. "Smart of Prew, making up a name for a ship he hasn't got. All he has is a subsea wireless. Do you know what's waiting off this reef?"

Men shook their heads.

"A cruiser," chuckled Sergon. "Say-those torpedoes of ours will cut a cruiser's armor like cheese! She's a pretty old baby"-he was looking through the periscope-"and if one don't sink her, we'll send another. If she's got destroyers hiding in back of her, we'll shake those buzzards like we always have!"

The door of the overfilled storeroom was open. Sergon didn't like its looks; he turned on a light and glared about suspiciously. Satisfied that Claudette had released no prisoners, to make them stowaways, he pointed to the torpedo room.

Two men entered; they lifted the top torpedo from the stack. Lugging the fifteen-foot cylinder, they pointed it toward a torpedo tube. As they shifted the fat torpedo, it toppled, off balance.

"Look out!" bawled Sergon. "Hang on to it!"

They couldn't hold on. Nose end, the torpedo hit the floor. Its head bashed loose, the maincylinder rolled sideward. Sergon, dropping back along the pa.s.sage, had expected a disaster; he gruffed his relief when he thought the danger past.

There was a yell from the men in the torpedo room. With it, the sharp bark of a gun. Sergon bounded forward as another shot was fired. He saw his men sprawling to the floor. Then, he spied the torpedo aiming for himself!

That, at least, was the illusion that Sergon gained. Where the torpedo head had been, a face was peering forth; below it, a shoulder; then a hand with a smoking revolver. For a moment, the thing on the floor was half torpedo, half man; then Sergon realized that it was a man inside of a torpedo sh.e.l.l.

The laugh that rang through the torpedo room left no doubt regarding the ident.i.ty of that fighter who had stowed himself inside the cramped container. Sergon recognized the avenger as quickly as did Claudette.

The Shadow!

TO Sergon, The Shadow's arrival was incredible, even though he wore a torpedo instead of a black cloak. To Claudette, realization was immediate. The Shadow had seen Sergon pa.s.s. Instead of remaining in the grotto, he had doubled back into the Barracuda to share Claudette's own danger.

Again, flame spat from The Shadow's gun. The weapon was Prew's .38 revolver, and with The Shadow's aim, the borrowed firearm should have proven as deadly as a .45 automatic.

All that saved Sergon was a roll of the torpedo.

The shot went wide. Backing along the pa.s.sage, Sergon whipped out a gun himself. By that time, The Shadow had grabbed the doorway, to haul his body from the cylinder that held it.

Two guns spoke at once; Sergon's shot was badly aimed, while The Shadow's missed only because Claudette's captors were lunging toward him.

The girl was grabbing at their gun hands, when The Shadow dropped one with an upward shot. On his feet, he downed the other while the fellow fumbled. Sergon was gone, dashing toward the control room. s.n.a.t.c.hing up unfired guns, The Shadow kept one, gave the other to Claudette.

The light by the stairway was blinking: "Ready... ready... ready -"

The Shadow ignored it. The signal was from Prew, to be understood and answered by The Shadow or Claudette, if either were aboard. But The Shadow preferred any risk rather than stop the final stroke that he had ordered, and he knew that Claudette felt the same way.

At a pace that Sergon had not expected, The Shadow reached the control room. He was blasting shots as he came, his bullets stabbing the guards who tried to stop him. Sergon was trying to yank the rudder lever, to send the ship into a dive, when The Shadow grappled with him.

Guns were lost in that hand-to-hand fray. The final weapon that staggered Sergon was the rudder lever, ripped from its place by The Shadow. Flooring Sergon with a hard swing, The Shadow was away again, to rejoin Claudette.

The girl was cowing crew members with her gun. They ducked as The Shadow swung the lever toward them. When they came about, they saw The Shadow and Claudette upon the stairs. The pair reached the top ahead of followers; there, The Shadow shoved the controls that raised the cylindrical wall and opened the top of the conning tower. He shoved Claudette over the rising wall and sprang after her. A man had followed them, was aiming from the pa.s.sage, but The Shadow s.n.a.t.c.hed Claudette's gun and beat the fellow to the shot. Two seconds later, the slowly rising cylinder had closed. The Shadow was urging Claudette up the ladder.

The Barracuda was riding the sea awash. That opening above still afforded a chance for escape. They were almost to the top when the Z-boat jumped forward, signifying that Sergon had managed to yank the speed lever, as a last resort. But that lunge was not the only one the Barracuda took.

Just as The Shadow rolled Claudette from the conning tower, the Z-boat heaved into the air.

Something had driven up beneath it, to prod it with a mighty slice that ripped half the bottom from the craft.

Claudette was hurled far clear; as she struck the water, she saw The Shadow take a sidewise dive from the tilted conning tower.

Reeling like some sea monster wounded in a fray, the Barracuda wallowed away along the surface. She was stricken beyond repair, succ.u.mbing to the gash that was pouring water into her hull. That was recognized by the waiting cruiser. Her guns were already opening fire.

The Shadow and Claudette were safely out of range, for the Barracuda still had speed. They saw the sh.e.l.ls explode about her; then one struck the conning tower when she was a quarter mile away. When that happened, they were swimming no longer.

Up from the sea beneath them had come a rounded platform: the deck of the Lamprey.

Prew's ship was intact, except for a battered prow. The Lamprey was the monster that had doomed the Barracuda. From a hidden channel, she had sneaked along beneath the pirate submarine, then driven up to rip her.