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.