Part 3

“You sure came out of it in a hurry, though, Don!” laughed Red Pennington, rather shakily. “I’d no sooner picked you up off the deck than you up and socked me in the eye!”

“I’m still slug-nutty; so you’d better watch out, Mercedes!” grinned Don, taking the glass of water the girl handed him. “But, seriously, I’d like to know who downed me, and why. Have you any idea, Captain Riggs?”

“Yes, Commander,” answered the officer gloomily. “I believe it was a brutal attempt at murder by some one of the enlisted personnel. I shall do my best to hunt the scoundrel down before we reach port. Meantime, I can only blame myself for leaving you alone. If I had not returned when I did....”

“Don’t take it that way, Captain!” protested Don Winslow, earnestly. “You weren’t to blame. And as for the notion of a murder attempt—wouldn’t a killer have used something surer than a blackjack and chloroform? Those things are a thief’s weapons.”

“Exactly, Commander!” spoke the deep voice of Michael Splendor. “Ye’ve named the means and the motive all in the same breath. A theft it was, to be sure; and if ye’ll just glance about the place, ye’ll see quick enough what the rascal stole.”

A startled silence fell upon the other five persons in the cabin. It was broken when Don, struggling up from his chair, cried sharply:

“The enlistment records! They’re gone, the whole stack of them!”

VI

MURDER BELOW DECKS

One mystery had been solved, but it had given rise to a more sinister problem. Michael Splendor was the one who pointed this out, as Don Winslow and his friends sat that evening at the officers’ mess.

How, he asked, could the thief have known Don was making a search of the enlistment records?

There were various answers offered on the spur of the moment. Mercedes Colby suggested that Don and the captain had been overheard talking about it on their way to the cabin; but that point was quickly settled. Neither man had mentioned it before reaching Riggs’ cabin.

Red’s answer was that the thief had happened to see Don through the open door, as he sat at the captain’s table. This sounded reasonable, until Michael Splendor told them he had tried looking through the door. From outside the cabin, he stated, neither table nor record file could be seen.

“The conclusion is, me friends,” he said with a troubled frown, “that the man who struck down Commander Winslow knew in advance what he was going to do, and why. He had time to plan the job, and wait for his chance to catch his victim alone. _He knew the_ _very moment we decided to search those records for a clue!_”

In the shocked silence which followed Splendor’s words, Riggs pushed back his chair. The captain’s face had the look of a man just charged with murder.

“In other words, you accuse me, Mr. Splendor!” he said hoarsely, rising to his feet. “By George, sir! If you were not a cripple, I would....”

“Please, Captain Riggs!” the voice of Michael Splendor rang sharp as a trumpet call. “I am accusing no one of us—least of all yourself. Now, look me in the eye and smile, me friend; for in faith I would sooner accuse meself than anyone in this cabin!”

Slowly the color came back into Captain Riggs’ cheeks. Sinking back into his chair at the head of the table, he did his best to smile, though it was a hard attempt.

“I believe you, Mr. Splendor!” he said huskily. “But the way you put the evidence gave me an ugly start, sir. It seemed to point to me alone as the attacker, or at least as the one person whose whereabouts were unaccounted for at the time of the attack on Winslow.”

“Indeed it did, Captain,” admitted the man in the wheel chair, apologetically, “and sorry I am for not choosing me words more carefully! I was just tryin’ to show all of ye how closely we are being spied upon. I meself could have sworn that no one was in earshot of our party this afternoon. Yet our every speech was heard and noted by the enemy. Our future plans must be told in whispers behind locked doors, I fancy.”

Throughout the rest of the meal there was a lively argument about dictaphones and other means of eavesdropping which the spy might have used. It all proved highly amusing to the Scorpion spy, who was listening in on every word, by the aid of a clever electrical “ear.”

Small and easily concealed as a man’s wrist watch, the device was a powerful amplifier of ordinary sounds. These were transmitted over threadlike wires to an earphone, palmed in the spy’s hand.

Turned toward a ship’s ventilator or porthole, or toward a party conversing on deck, the mechanical “ear” could pick up even whispered speech without the slightest difficulty.

But while this comparatively harmless eavesdropping was in progress, a far more sinister drama was being enacted below decks. It was the old, old game of death, which has been played since life began upon the earth, and the first killer stalked his unsuspecting prey.

Deep in the bowels of the ship, amid the click and whir of oiled machinery, Chief Petty Officer Ahern began his evening watch. He was a man of about thirty years, with a well-muscled body, and keen, blue Irish eyes. In six years he had risen from Fireman Second Class to Chief Machinist’s Mate.

At the moment, Ahern was the only man in the engine room of the _Gatoon_. Lieutenant Allen, the Engineer Officer, was in his own stateroom, cleaning up for the evening meal. The other Machinist’s Mates were off watch. The nearest members of the “black gang” were sweating in the boiler room, forward.

Ahern was whistling an old Irish ditty as he moved about, checking the smoothly running machinery. Thought of danger was the farthest thing from his mind as he paused to glance up at the stars shining through the fiddley hatch above his head.

All at once his body stiffened as if in agony. His hands clawed at his throat. Mouth open and eyes popping from their sockets, he reeled backward in a grotesque dance of death.

As he fell, struggling, to the iron deck, a man in ordinary seaman’s uniform dodged past him toward the main steam line. There was a quick sharp hammering; a hiss of escaping steam. Then the seaman reappeared, his features covered by a white handkerchief.

Briefly he stooped over Ahern’s limp body, fumbling at the swollen, purple neck. The next moment, swift as a startled rat, he slipped out of sight behind a bulkhead.

Five minutes later, Lieutenant Allen came on deck for a breath of air before going to mess. Glancing toward the fiddley hatch, he noticed a wisp of steamy vapor rising from it. In alarm he sprang forward to look below. The heavy reek of hot engine oil met his nostrils as he bent over the hatch. The hum and clink of smoothly moving metal rose with it to reassure him. Only the steamy mist between decks, and a slowing of the engine’s rhythmic beat spelled danger to the officer.

Turning to the engine room ladder, Lieutenant Allen made the lower deck in record time. Through a mist of steam, he made out the body of the Chief Machinist’s Mate. Pausing beside it only long enough to read the signs of death, he pressed on as far as he dared toward the broken steam line.

Up on the _Gatoon’s_ bridge, Lieutenant Darnley caught the engine room’s urgent signal. Picking up the speaking tube, he barked a short acknowledgement.

“Allen speaking,” came the terse reply. “Inform Captain Riggs of attempt to sabotage the ship’s engines. Chief Machinist’s Mate Ahern is dead at his post. Must stop engines and pull boiler fires at once.”

The meal was just over in the officers’ mess. With a low exclamation Don Winslow jumped up and stepped to the nearest porthole.

“If I’m not mistaken, Captain,” he said, turning to face the others, “this ship is losing way. The engines, ... hear that, sir? The vibration has stopped completely!”

Captain Riggs sprang to his feet, scowling.

“You’re right, Commander!” he cried. “We’ll be losing steerage way in a few moments. I’ll ring the bridge and find out....”

A heavy knocking on the cabin door interrupted. Opening it, the captain faced a breathless yeoman, whose message of disaster fairly tumbled from his lips.

“Trouble with the main steam line, sir!” the enlisted man reported. “And the Chief Machinist’s Mate has met with an accident, too. Lieutenant Allen requests your presence at once in the engine room!”

VII

“MAN OVERBOARD!”

Shoulder to shoulder with Captain Riggs, Don Winslow made for the engine room ladder. In their wake hurried the medical officer and Lieutenant Red Pennington. Mercedes, at Michael Splendor’s insistence, stayed behind in the cabin.

Not one of them believed that the “accidents” reported by the yeoman were at all accidental. With Scorpion spies aboard trouble could be expected from any quarter. Unfortunately, there was no guessing in advance where disaster would break out; or treachery, for that matter. Even as the _Gatoon’s_ afterguard was bending over Ahern’s twisted corpse in the engine room, a shadowy form slipped into the radio shack, abaft the galley. In the faint glow of a shaded bulb, the man’s face was a mere blur. Only his hands showed in dark outline, as they fingered a pair of invisible dials.

Abruptly the fellow sat down, his right hand now concealed beneath the table. A faint, almost inaudible clicking began spelling out in International Morse Code: “SCP—SCP—Acknowledge—SPC—SPC....”

Almost immediately came the reply—a hoarse, murmuring voice from outer space: “_Go ahead SC-3 with your report._”

Again the faint ticking filled the tiny room.

“Orders carried out,” it spelled rapidly. “Engines disabled for the next twenty-four hours. CS-3.”

There was silence for a full minute. Then the voice in the radiophone breathed harshly: “The master is pleased. Stand by at midnight for further instructions. That is all.”

Below decks the _Gatoon’s_ medical officer rose, white-faced, from his examination of the Chief Machinist’s Mate.

“This man is dead, though the body is still quite warm!” he stated. “I should say he had been strangled by a noose of thin wire, which became embedded in the flesh. Somebody removed the thing before we got here.”

Lieutenant Allen, catching the captain’s glance of query, shook his head.

“I didn’t touch Ahern, except to turn him over, sir,” he declared. “And there was no one else in the engine room when I arrived. Strange way to kill a man, with a wire noose!”

“The French call it '_La Garrote_,’” observed Don Winslow, stooping to pick a peculiar metal object from a dark corner of the deck. “If I’m not mistaken, this thing is it! Looks as if the killer dropped it in his hurry to get away.”

At his words the others turned to stare in fascinated horror. The death instrument was a loop of extremely thin but tough steel wire, threaded through a small metal hand grip. A sharp pull on the latter tightened and locked the strangling noose in the same motion.

“See!” remarked the young Intelligence Officer. “A man could hide this weapon in his closed hand, or slip it into a watch pocket. It’s deadlier than a knife in the back. Look here, Captain! No need to let the crew know just how Ahern was killed, is there? A thing like this could demoralize a ship’s company in no time!”

The grizzled ship’s master met Don’s look in thoughtful silence.

“I understand, Commander,” he said at last. “Knowing what _we_ do, every enlisted man aboard would be suspecting his mates—afraid to turn his back for a second, for fear of feeling his wind shut off! You’re right about keeping it quiet. We’ll put poor Ahern in the bos’n’s locker, and take the key away. Then the engine crew can get busy at that broken steam line.... How long before we can get under way again, Lieutenant?”

Lieutenant Allen shook his head.

“If it were only the steam line, I’d say four or five hours, sir,” he replied dubiously. “But I saw what looked like emery dust near the main shaft bearings. If any of that stuff’s been used we might not make port for a week, if then. All depends on what we find in the next hour, sir!”

“And on how close a watch we keep after that, Captain!” put in Don Winslow. “I’d suggest an armed guard be stationed at every vital part of this ship. Lieutenant Pennington and I will help you keep watch topside, sir.”

Tossing a wink over his shoulder to Red, he turned to the ladder leading on deck.

Sometime after midnight the two young officers stood shoulder to shoulder in the shadow of a port lifeboat, the wind blowing their whispered words out to sea.

“Got your automatic handy, Red?” Don asked casually, resting an arm on the ship’s rail. “We’re part of that guard I mentioned to Captain Riggs, you know. The difference is that we’re not stationed anywhere in particular.”

“I cleaned and loaded my gun before mess gear blew this evening,” young Pennington answered. “But, say! Do you really think there’ll be another attempt to put the _Gatoon_ out of commission?”

“I do,” Don replied, “though mere sabotage wouldn’t be the Scorpion’s real object. He doesn’t go in for small-time stuff. He’d like to sink us all without a trace, and if I didn’t know that we’d destroyed his pirate submarine....”

“But maybe he’s got another we don’t know about!” cut in Red excitedly. “With her engines crippled, this old cutter’d be an easy mark for a torpedo. Or for any armed yacht the Scorpion might have handy. Say, Don, I’ll bet that’s the answer!”

“Keep your shirt on, Red!” Don Winslow laughed softly. “Your theory sounds okay, if you say it fast, but don’t let it scare you off on a wrong tack. I’d stake my commission, on there _not_ being another enemy submarine in these waters; and as for an armed yacht attacking us—well, the _Gatoon’s_ guns outrange any but a destroyer’s. No! There’s some worse danger afloat, and it’s up to us....”

Don’s words trailed off into silence. Stepping deeper into the lifeboat’s shadow, his form was suddenly blotted out.

“Red!” came his low call, above the slosh of waves against the ship’s side.

At once, the stocky lieutenant moved in the direction of Don’s voice. Feeling his way along the lifeboat’s keel, he felt his arm grasped firmly. An instant later an end of light cordage was pressed into his hand.

“That’s the second I’ve located,” Don Winslow whispered in his friend’s ear. “My hand happened to find the first one by accident. What do you make of it?”

“Why—it’s a boat lashing, Don!” muttered Red, wonderingly. “That means the tarpaulin’s loose, and a stiff breeze would lift it.... Huh! You don’t suppose that’s where the killer’s hiding himself—right in this boat above our heads?”

“He may have hidden _anything_!” Don answered briefly. “Here, let me stand on your shoulders and take a look!”

As Red braced himself, Don went up, catlike, to grip the lifeboat’s gunwhale. Fishing in a pocket, he produced a small flashlight. It’s beam, thrust under the canvas boat cover, lighted up the whole cavelike space beneath.

Red, crouched in the darkness below, felt Don’s weight suddenly leave his shoulders. Glancing up, he saw his friend’s dim form disappearing inside the boat.

Moments passed, with only a faint whisper of movement from inside the covered lifeboat. Red Pennington waited nervously at his post, alert for the slightest sound of approaching footsteps. If the spy had hidden something of value, the fellow might be coming back for it at any time!

Red’s reasoning was better than his hearing, as a matter of fact. When he did hear the faint step behind him, it was too late to turn. Jerking his head to one side, the stocky lieutenant just saved himself.

A numbing blow descended on his shoulder. With a grunt, Red whirled, his fist coming up in a wicked hook which contacted flesh and bone. The unseen assailant’s gasp of pain came a second before Red’s whoop: “I’ve got him, Don! Come—ugh!”

The thug’s elbow jammed into Red’s midriff, and loosened a perfectly good hammer lock. The lieutenant gagged, lost his grip and his footing together, as the enemy tripped him with a jiu-jitsu trick.

At that second, Don Winslow’s lithe form dropped from above.

Only darkness and the snakelike agility of the Scorpion spy prevented his capture then and there. The man leaped over Red’s body, barely avoiding Don’s rush, and jumped for the rail beyond the lifeboat.

Red, scrambling to his feet, lunged for the boat’s forward end. Without warning there came a heavy splash from overside. Don’s shout, “Man overboard!” followed instantly.

“G-great guns, Don!” Red gulped, bringing up against the rail. “I thought he’d knocked _you_ overside! What happened, anyway?”

“He jumped!” clipped Don Winslow as other voices on deck and bridge took up the cry of “_Man overboard!_” “Listen, Red! You hustle aft and get a place in the first boat that’s lowered. Don’t tell ’em the whole story—only that someone attacked you and jumped overboard when you fought back. Lively now, before anybody sees us together!”

Badly mystified, Red Pennington trotted aft to the group gathering around Number Three lifeboat. He had a hundred questions to ask, starting with: Why was Don staying behind? On the other hand, orders were orders, and questions would keep until Don chose to answer them.

VIII

THE SECOND ATTACK

Sixty seconds from the moment Don shouted warning, Number Three lifeboat was swinging, fully manned, from her davits. On the dark water below, two life preservers, with patent flares attached, floated along the _Gatoon’s_ portside. The ship, with engines dead, rolled gently in the trough of a gentle ground swell.

For a rescue at night, no better conditions could be asked. The trouble was that, from the moment Red Pennington’s attacker had hit the water, there had been no sign of him. No second splash or cry for help had been heard.

Was the fellow a suicide—deliberately drowning in preference to being caught? Or had he just gone down, unable to swim?

One guess was as good as another. Except that the man was a Scorpion agent, Don Winslow would have given the fellow up for lost. As it was, he suspected a trick.

Thinking back, he recalled that the spy had not hit the water all sprawled out like a man who had lost his balance. There had been only the single, clean _plunk_ of an expert dive.

But where, in mid-ocean, could the man have swum? To a waiting boat, somewhere out of sight in the darkness?

There was one more alternative. As the idea flashed across Don’s brain, he whirled and ran to the starboard rail. After sweeping the ship’s side in one quick glance, he turned again and darted back to the after deck.

Halted at the taffrail, the young officer leaned far over, his eyes squinting to pierce the darkness under the gunboat’s stern. After a moment, he straightened up with a satisfied nod, and strode back to the portside.

A little group of ship’s officers stood beside Mercedes and Michael Splendor near the davits, just as Don approached. All of them caught the young commander’s quiet words.

“Send your boat around under the stern, Captain Riggs,” Don Winslow murmured. “Our man is there, clinging to the rudder post. If we go softly, we can all get back to the taffrail in time to see the fun!”

For an instant Riggs stared in unbelief, then turned to snap an order at the men below. As the oars resumed their steady stroke alongside, Don led his friends aft on tiptoe. He knew the questions they wanted to ask; but there was no time now for talk.

A few feet from the taffrail, Don signaled the two ship’s officers to stand by. He himself stooped with one hand on the line of the taffrail log.

The wait was not long. As the lifeboat started to round the stern, the stout line under Don’s fingers jerked taut. By its motion he knew that his man was climbing, hand over hand.

Only a trained athlete could have performed such a feat, for the line was barely thick enough to hold a man’s weight. The climber’s hands must have been cut raw after the first half dozen grips, but he came doggedly on. At the last moment before his head appeared, Don drew back in a wrestler’s crouch.

A lunge, a harsh oath, a brief, desperate struggle, and it was over. The unknown, who had attacked Red Pennington and then plunged into the sea, now stood on deck, panting in the grip of three strong men.

“So what?” he demanded insolently. “Now ya got me, wot ya gonna do with me? I ain’t done nothin’ wrong. A guy up an’ slugs me in the dark, an’ I fall overboard, an’ now ya grab me. So what!”

Don’s flashlight, turned on the man’s face showed a pair of small, ratty eyes set in animallike features. The fellow was desperate, and trying to cover it up with a line of bluff.

“Looks as if we’d caught our murderer, all right!” gritted Captain Riggs, after a shrewd glance. “This seaman is one of the replacements we took on in Guantanamo. Shall I throw him in the brig now, Commander, or do you wish to question him first?”

Don Winslow snapped out his light.

“The questioning had better wait, Captain,” he replied quickly. “I’ve just discovered something that may be of vital importance to us and every honest sailor aboard. Suppose we all talk it over in your cabin, as soon as this spy is safely under lock and key!”

On his way to the captain’s quarters, Don Winslow stopped by Number Three davits and waited until the lifeboat had been swung inboard with its crew. As Red Pennington stepped to the deck, the young commander seized his arm and led him back into the shadows amidships. A few quick words covered the rat-faced seaman’s capture.

“And now we’ll see what his game was, Red,” Don whispered, moving over to the port rail. “Give me a boost up into that boat with the unlashed cover and stand by for trouble. But don’t let anybody slug you from behind this time!”

“I won’t, don’t kid yourself!” muttered the stocky lieutenant, stooping to take Don’s weight. “But, say! You must have found something up there the first time, or you wouldn’t be so anxious to look again. Can’t you wait long enough to tell a man...?”

But Don was already over the gunwhale and inside the boat. This time several minutes passed before his head and shoulders appeared from under the tarpaulin.

“Take these, Red!” he said softly, passing down a loose packet of papers. “And put them out of sight. I’m coming down now.”

Swinging light to the deck, he drew his pocket gun and led the way back aft.

“Wha-what the dickens?” muttered Red Pennington in a hoarse whisper, as he shoved the papers under his waistband.

“Enlistment records—the missing ones!” hissed Don, glancing along the shadowy decks. “They were just part of what I found in the boat. If anybody tries to take them away from you between here and the captain’s quarters....”

WHAM! BANG!

A tongue of flame had lanced out from behind the darkened galley. In the same split second had come Don’s answering shot. Without pausing the young commander leaped straight toward the source of attack.

Red, pounding at Don’s heels, tugged out his pistol.

“I’ll take the starboard side!” he yelped as Don darted to port.

It seemed that the enemy, whoever he was, must be trapped, or he would have to break away in full view and get shot.

Yet it was Red Pennington whom Don bumped into, just abaft the galley.

“G-gosh! I nearly shot you, Don!” gulped the stout lieutenant. “Where’n thunder did that bird go, anyway? I was sure you were he, till I got a second look!”

For answer Don seized the knob of the galley door. It flew open to reveal a dimly lighted interior, fragrant with the smell of brewing coffee. Backed up in a corner stood Johnson, the colored cook, brandishing a razor-sharp meat axe.

“Stay right wheah yo’ are, befo’ ah scattahs you’ brains!” wailed the terrified man.

Don stepped calmly across the threshold.

“It’s all right, Johnson,” he said, sweeping the galley with a quick look. “Somebody shot at us just now, and we thought he might have ducked in here. Of course, you didn’t see anybody?”

Johnson’s meat cleaver hit the deck with a loud clang.