Amelia Tucker gave a short, nervous laugh.
"Communist Party?" Her voice was pitched high; a fixed smile played about her mouth.
"That's right," Blake said grimly. "When did you join?"
"Wha--?" She went white.
Sexton Blake's eyes burned brightly. "That list of communist agents you gave the rebels was false. The real communists are still at large! Juan Callas has made prisoners of his most loyal supporters. You set it up like that. Deliberately. You've been getting your orders from the Soviet agent -- Harben!"
"Harben...?" she echoed, numbed.
"And now that Jules Harben isn't around any more," Blake went on savagely, "you're giving all the orders yourself! That makes you a pretty big fish in the Soviet millpond. I'd say you've been a member of the party for a long, long time..."
"You are calling me a communist?!" Amelia Tucker rallied her strength for a sudden show of vehemence. "You calling me a communist? You're being utterly fantastic! Would I have got you out of that Fascist gaol if I was Red--?"
Blake gave a slow, grim nod. "Yes, you would. First you framed me for Worple's murder to get me in -- and out of the way -- but then you met Francesca who told you how much I'd already learned. From then on you were frightened because I knew too much and you were scared I'd talk to the authorities. So you had to get me out again -- and get rid of me some other way. You were going to have me quietly killed -- just as you killed Sellingham when he found out that the list of agents you planted was phoney! Is that how it happened? Did young Sellingham stumble on the truth?"
Amelia Tucker had gone as white as chalk. Faltering, almost groping, she reached for her desk and leaned against it for support. "It's not true---" she choked. "It simply isn't true--" She began pulling herself together.
Too late, Blake saw the swift, sharp movement of her left hand as it sped at the heavy cigarette case beside the desk blotter...
In the next instant the woman had spun around, all trace of her distraut condition gone, as she flicked up the lid of the box and grabbed the midget-sized automatic which lay inside.
The gun pointed steadily ar Blake's abdomen.
"All right, Mr. clever Blake--" a leer of triumph was spread across the woman's face "--so you're a very smart detective! It's a pity you weren't smart enough to stay out of other people's business! You're right -- I am a communist! I've been communist since nineteen forty-five and proud of it!"
She paused for breath, he eyes glittering. "We're going to take over this country and clean it up. Juan Callas is a fool; he wouldn't know where to begin reforming this hotbed of corruption! This country's going to be cleaned up the proper way -- only you, Mr. smart-alec Blake, aren't going to be around to see the results!"
"Killing me," Blake said quietly, "isn't going to solve anything. I'm not the only person who knows about you. Your days are numbered..." It was a desperate lie, but Blake knew it was the one slim chance that might save him. "You can't get away with it! The real list of Red agents is already in Western hands--"
Amelia Tucker threw back her head and laughed in scorn. "You fool!" she exclaimed. "You poor, idiotic fool. The real list of agent's will never be found by anyone. It died with Peter Sellingham -- the only copy in existance! He died because he found it; stumbled on it by pure chance. But you, Mr. Sexton Blake -- you are going to die for nothing!"
With a final hiss of venomous triumph, Amelia Tucker gripped the midget pistol. Her finger tightened on the trigger.
Blake braced himself for the end.
He heard the shot ring out; stunningly loud, like the crack of a whip. But he felt nothing. Nothing touched him.
Then incredibly, unbelievably, he saw an expression of blank, choking astonishment on Amelia Tucker's face.
She lurched forward. Steadied herself. She clutched a hand to her neck which was suddenly pulsing out blood.
Then with a final, unbelieving gasp she rocked backwards, tottered for a bare instant -- and crashed earthwards in a lifeless heap.
Blake's eyes slowly rose and moved towards the door.
In the open doorway, Captain Juan Tarratona of the Maliba State Police stared at the corpse with a faint, quizzical frown before blowing the smoke from his revolver and slipping it into the holster at his belt.
"It is amazing, Seņor Blake," he said thoughtfully, "how much trouble in this world is caused by misguided idealism."
Still frowning thoughtfully he looked back at the dead body and added: "Of all the people in Maliba, she was the last person I ever suspected. It would seem," he sighed, "there are no true ladies any more."
* * *
"How much did you hear?" Blake demanded as soon as he recovered from his surprise.
"Enough to justify the expenditure of my bullet," said Tarratona. "Perhaps I should explain my presence: just after you left headquarters, a report came in from one of my informers that Miss Tucker was observed at the scene of the murder last night. I thought it odd that she did not mention it to me. Even so, I only came here to ask. It did not occur to me that such a woman could have committed the crime. She must have been a very clever woman..."
"A very highly-trained one," Blake said grimly.
"Si," Tarratona nodded. "I never suspected that it was she who was controlling the Communists..."
"I'm not sure that it was," Blake said bleakly.
Tarratona looked at him sharply. "You mean there is someone else?"
Blake nodded. "There must be. And we've got to find out who before--" He broke off hesitating.
Captain Tarratona said tiredly: "Seņor Blake -- you make speak freely. It is no secret to me that the present government is about to be swept from power. Revolutions come and revolutions go... but Tarratona always stays. No-one can run this country without me; therefore I bow willingly to the inevitability of progress. In any case, the country is due for a cleaning up. Revolutions are always invigorating."
Blake smiled thinly. He had no intention of divulging any confidences to the police chief. But for the moment their interests coincided.
Blake said: "I'm not sure who is controlling the Soviet network here -- but I'm pretty sure I know where I can find out..."
"My car is waiting outside," Tarratona said suavely.
"It's going to take more than a car," Blake said grimly. "We've got to get to the research ship, Gorgon -- and we haven't a moment to lose."
* * *
A high-speed police lauch took Blake and Tarratona on the second lap of their journey to Professor Hoddard Curtis's Gorgon.
In the bright, sharp morning sun the sea was a molten silver. The waves slapped viciously against the side of the launch, for it was a rough sea despite the heat, and a strong breeze was blowing.
Curtis himself met them as they climbed the ladder and reached the deck. The salvage operation was under way.
Hanging from the derricks on the opposite side of the ship, the bathysphere swung in its cradle like a great egg -- the spawn of the monster like-ship.
The sphere was just being swung onto the deck.
Crew-men sweated with hawsers to secure it as the winches lowered it on to a cleared space.
Curtis nodded to his two guests to approach. "Don't go too close," he warned. "I'm going to have to use this." He indicated an oxy-acetylene welding kit which was being wheeled up by the mate. At the same time he donned a pair of goggles, explaining: "The sphere can only be opened from the inside. We built it that was as a safety precaution."
A moment later the torch was flaring incandescently in the young professor's hands as he went to work on the bathysphere's hatch.
It took several minutes before the door swung inwards, but finally it yielded.
The young biologist switched off the torch and stared into the murky confines of the sphere. He shuddered and looked away. His face was pale. "Worse than ever," he gulped. "The eels have had a pretty good meal... it's ugly..."
Blake and Tarratona moved forward. Blake was there first. He peered into the sphere. He had to fight down a surge of nausea at what he saw. It was gruesome. The corpse inside was unrecognisable. But the knife in the back was plain to see. The man had been murdered all right.
Then Blake saw something else. Something which set his mind thinking swiftly -- until suddenly he realised what it was. And then, at last, the answer to all his questions began to click into place. He knew how the murder had been committed!
* * *
It took the best part of twenty minutes to empty the complete contents of the bathysphere on to the deck. By the time Curtis had completed an initial check of all the equipment, the spectators had been joined by the two FBI men, Navarro and Kellaher.
There was a grim silence as they all gazed at the dead body.
Curtis turned to Blake: "Well, Mr. Blake ... You wanted to be here to identify the corpse. Can you make anything of it? Are you satisfied this is Harben?"
"I'm satisfied," Blake said quietly, "that this isn't Harben."
"Whatssat?" Lieutenant Navarro suddenly turned a pair of fierce eyes on the detective.
"I said," Blake repeated quietly, "it is not Harben."
"Not Harben?" demanded Kellaher. "What do you mean, not Harben?"
Blake said grimly: "Was there ever any reason to assume it was Harben? When this bathysphere went down there were two men aboard. Only one body has been recovered and as we can all see, it's unrecognisable. Why should be assume it belongs to one and not the other?"
"For one very good reason," interrupted the American Professor. "Harben was the one we heard screaming out for help just before the bathysphere broke loose -- at more than seven hundred feet."
Blake nodded. "And that's precisely what tells me you've picked the wrong man. Professor, take a look at all the equipment. Are you satisfied that it's all here?"
"It's all here," Curtis said firmly without looking.
"Very well," said Blake. "Consider this: when the impossible has been eliminated, what remains must be the truth, agreed?"
"We all know that no-one could have left the bathysphere at seven hundred feet," said Blake.
"Check," said the biologist. "At that pressure no-one could open the hatch."
"And even if they could, they'd die as soon as they did?"
"Very well, then it follows inevitably that the man who left the bathysphere must have done so much earlier -- at not more than say fifty feet?"
Curtis frowned. "True... with an aqualung it could be done..."
"Then that's what must have happened," Blake said flatly.
The FBI man, Kellaher, interrupted with an exasperated snarl: "If the killer left the bathysphere at fifty feet, how could he have killed the other guy at seven hundred?"
Blake looked at him calmly. "He couldn't, could he? So that's one possibility eliminated. He must have killed his victim before reaching fifty feet."
Curtis looked at Blake with a baleful glare. "We're going around in circles! If this guy was dead at fifty feet. how come he was heard screaming at seven hundred?"
Blake said patiently: "Once again, the answer is he couldn't have been. Therefore he wasn't."
"The mate was on the radiophone!" snapped Curtis. "He heard Harben screaming when the bathysphere was at seven hundred feet!"
Blake nodded patiently. "And this proves what I've been saying all along: Harben's screams were heard after the murder had been committed -- therefore Harben could not have been the murdered man -- so by a process of elimination he must have been the killer."
"Now wait a minute--" Curtis began to get angry.
Blake cut him short. "Professor -- take another look at the equipment. You say it's all here?"
"It's all here!" snapped Curtis.
"And if you look carefully," Blake insisted, "I think you'll see something that shouldn't be there."
Curtis frowned suddenly. His gaze flicked across the deck. It began scanning the piles of equipment. And suddenly, sharply, he let out an exclamation.
"I thought so!" Blake strode grimly across to the object and picked it up.
It was a small, battery-powered tape recorder. "What the mate heard on the radiophone," Blake said grimly, "was not a man at all -- it was this. When the tape is dryed out and played back you'll be able to here the spine-chilling commentary designed to simulate the dying agony of a man being consumed by an unknown sea monster. All it need to complete the crime was a small charge of explosives to cut the sphere adrift -- to sink it to the ocean bed and destroy all the evidence."
Blake paused, eyeing the listeners bleakly.
"The tape recording was made by the murderer long before the sphere sank -- and played back after the murder had been committed. Since the voice was identified by the mate as that of Harben, it follows simply and clearly that Harben was the killer."
There was a stunned silence before Curtis demanded: "Then who's this?" He pointed at the mutilated corpse.
"This is a man called Linwood -- whose real name is Peter Sellingham."
Curtis looked dazed. "But why?" he demanded fiercely. "Why did Harben have to kill him?"
"The reason for that is probably here..." Blake strode across to the corpse and unbuttoned the pockets on what remained of the dead man's denim overalls.
In the third pocket he found what he was looking for -- a sheaf of sodden, but still readable, typescript pages.
"Harben," Blake explained quietly, "was a Soviet agent plotting to infiltrate the Maliban Liberation Movement with a view to turning this island into a Russian satellite. The murdered man here, Sellingham, had found out; he also found out the names of every red agent on the island -- here on this list."
Blake held up a pulpy mass of papers.
"This list was originally compiled by the Maliban Secret Police. Later it was stolen by the communists who substituted it for a phoney list -- knowing that the phoney list, in turn, was to be stolen by the rebels."
"Because Sellingham sympathised with the rebel movement and had learned of the communist scheme, Harben had to kill him. At the same time, Harben had to arrange for himself to disappear. The bathysphere offered a foolproof was of killing two birds with one stone. Sellingham, being an amateur in the espionage game, wasn't aware that Harben knew how much he'd learned. It must have been easy enough to lure him out there with the promise of a deep sea dive..."
Blake broke off. He concluded thoughtfully: "Only the purest chance -- a ledge of rock eleven hundred feet down -- prevented the crime from remaining a perpetual mystery. It was very nearly the perfect murder."
Lieutenant Navarro of the FBI was looking at the detective with narrow eyes. "Mr. Blake, I'd like to see that list..."
"I'm sure you would," Blake smiled. "But I need it. You needn't worry though -- your government will be getting a copy in due course."
For the first time Blake produced his official credentials and showed Navarro his PAN-SAC card.
Navarro whistled. "I'm sure glad you're on our side! I thought you were going to be a sticky problem. Listen, there's something I've gotta know -- how did the Reds manage to switch the list of agents?"
"They had an agent working inside the Nonales government," said Blake, "the same man who imposed press censorship on the bathysphere story to cover up the murder."
"Who?" demanded Navarro. "Where is he? We've got to get him!"
"You've got him," Blake said with a thin smile. "He's right here -- aren't you, Captain Tarratona!"