They stared a little longer at the scene, then Lalla Dee turned from the wall.
"I think I'll go to bed," she told him. "I'll see you at breakfast, Mr. Idwall."
"A sweet kid," Crane thought as he left her at her cabin and walked on toward his own. Then the perilous task ahead of him claimed his thoughts. He must search Kin Nilga's cabin.
As he sat in his own dark cabin, waiting for the liner's passengers to retire, Crane's mind grappled with what lay ahead. If Kin Nilga was the possessor of the stolen brain, then entering the Saturnian's cabin was dangerous.
But he had to do it! Every hour that passed brought the Vulcan nearer Earth where Kin Nilga could easily trans-ship to another liner and throw him off the trail. And every hour increased the chance that one of the killer's diabolical attacks would take his life. Crane waited two hours, until silence filled the corridor. The last passengers had sought their cabins and only the ship's officers and men on duty in the control and rocket rooms remained up.
Then quietly the TSS man slipped out of his cabin, his hand resting on the hilt of his beam-pistol.
Except for the droning throb of the air-pumps, there was no sound as Rab Crane approached the door of Kin Nilga's cabin.
He stopped abruptly, stiffened, as he came opposite it. That door was slightly open. And from inside the Saturnian's dark cabin came a hoarse, smothered cry!
Crane shoved the door wide open, pistol aimed. He glimpsed a shadowy figure bending over the bunk, and even as he looked he heard a snap that could be only the dull cracking sound of a breaking neck!
Crane knew, in one swift flash of insight, that he had been wrong. Kin Nilga was not the killer! The real murderer was this squat, shadowy shape who had just slain Kin Nilga!
Crane rasped, "Stand where you are or I'll kill you!"
The shadowy killer turned, started across the dark room toward him with quick, heavy steps"
"Stop or I'll fire!" Crane warned. And when the shadow did not pause, the TSS man pulled the trigger of his beam gun.
The thin white beam from his pistol knifed the darkness of the cabin and struck the shadowy, indistinct form of his opponent squarely.
Yet the killer came on! Though Crane fired his deadly beam again straight into the advancing slayer, the shadow did not even falter as he lunged through the gloom at Crane!
CHAPTER III
VOICE OF THE BRAIN
Crane was so stupefied by the failure of his beams — which should have killed any living thing at this close range — to halt the killer, that he nearly lost his life. Before he turned to escape the remorseless figure had reached him.
Hands grabbed Crane in the most powerful grip he had ever felt, bruising his flesh to the bone by the tremendous strength of their grasp. He cried out hoarsely, struggling in the dark against that terrible clutch.
The grip shifted to his neck as Crane fought futilely to escape. Even as he struggled, the TSS man knew that another moment would see his neck snapped, as those of the guardsmen of Doctor Alph's house had snapped.
But his cry had been heard, and the alarmed voices of passengers in other cabins were suddenly audible. The killer, apparently alarmed, flung Rab Crane aside and leaped out of the cabin, his heavy steps receding rapidly down the corridor.
Crane, stunned by the impact and bruised by the other's iron grasp, staggered out of the darkened cabin as the people burst into the corridor and the lights were snapped on. The second mate of the Vulcan cried:
"What's the matter here-!' He shoved past Crane into the cabin, snapped on a light.
He stared at the bunk in which Kin Nilga the Saturnian lay dead, his great neck snapped like a straw, then recoiled in horror.
Then he turned on Rab Crane who was staggering, disheveled and bruised… "Why did you kill the Saturnian?" he snapped.
"I didn't kill him," said Crane. "I heard a row in here and came in. In the dark, the man who killed Kin Nilga jumped me, then escaped."
"A likely story!" cried the officer. "There's been a mysterious explosion and two murders on this liner since we left Venus. The explosion was in your corridor, the first murder was at your dining table. And now you're found over the body of the second victim… You're under arrest!" He had drawn his pistol, was covering Crane with it. Stunned by this disastrous turn of events, Crane saw the difficulty of his situation. He dared not tell them he was a TSS man, or that he sought the great secret from the stolen brain of Doctor Alph. This liner was a Venusian ship arid once these Venusians learned the brain was aboard, they'd search to the last corner to get it and its secret for Venus. Then he would be through and the secret lost forever.
"I'm sure you're wrong about Mr. Idwall," a girl's dismayed voice was telling, the officer. "He was nearly a victim of the radium poison himself, in the dining saloon."
It was Lalla Dee who was defending him.
Kark Al, the withered little Martian, nodded corroboration, snapping, "It's stupid to accuse Mr. Idwall of these killings."
"That will be for the captain to decide," the officer said inflexibly. "You'll have to come to his office at once," he told Crane. "The rest of you people return to your cabins."
As Rab Crane was forced by the officer's gun through the crowd of curious, horrified passengers, he managed to smile reassuringly at the pale, distressed Lalla Dee.
The TSS man's eyes were searching the crowd for Jurk Usk, the Jovian who had sat beside Kin Nilga at the dinner table. The Jovian, then, and not the Saturnian, must be, the killer. No one else on the ship, now, but the Jovian had such strength. And he could not see Jurk Usk anywhere.
Half an hour later, in the captain's office, the veteran, space-tanned Venusian who was master of the Vulcan faced Rab Crane.
"Mr. Idwall, all the evidence points to you as the murderer of Kin Nilga and of the Earthman," he said. "A search of Kin Nilga's effects has revealed that he was a member of the Saturnian Secret Service. It is obvious that you are a criminal he was pursuing, and that you tried to kill him in the dining saloon tonight, failed and succeeded later in killing him in his cabin. A table steward has said you questioned him about Kin Nilga's movements."
"But how could I have broken his neck like that?" Crane protested desperately. "No Earthman has such strength."
"I do not know just what means you used to murder him," the captain told him unrelentingly, "but our course is obvious. You will be the ship's brig until we where you will be turned over to the space-court for trial."
Crane was led away, down to the lowest deck of the great liner, and thrust into a narrow metal cell on a little corridor off the rocket rooms. He sat down heavily on the bunk.
In the dark cell, silent except for the steady throb of the ventilator, Crane wholeheartedly cursed the turn events had taken. Imprisoned here, he had no chance of securing the stolen brain before the Vulcan reached Earth.
It was plain now that Jurk Usk was the man he sought; that the squat surly Jovian was the shadowy figure who had stolen Doctor Alph's brain. Kin Nilga, an agent of Saturn, had been on the trail of the brain just as Crane was. Jurk Usk had killed Kin Nilga, and tried to kill Crane. Why, he asked himself, had his beams not affected the Jovian? And had it been Nilga or Usk who had killed the Doctor and his guardsmen?
Now, Crane thought hopelessly, the Jovian had a clear field. Kin Nilga of Saturn was dead and he, the agent of Earth, was in prison for the rest of the voyage. When the ship landed, Jurk Usk would go free with the brain and its doom-freighted secret.
That night passed slowly for the tormented TSS man. And after morning came — the morning of a space ship, marked only by the turning on of all the ship's lights — Crane's numbed brain fought frantically for a plan.