That was why John Dark had spared the lives of the two brothers when he had captured them in the freighter in which they were returning to Earth from Saturn. Ordinarily, the pirate leader would have ruthlessly killed them as he killed all prisoners who were not rich enough to pay ransom. But the fact that Ricky was a physician had saved them. The pirates needed a doctor. They had kept the two brothers prisoner on their ship for that reason. Kenniston and Ricky had still been on the _Falcon_ as prisoners, when the Patrol had finally caught up to it and wrecked it. "Dark knows that Ricky is a fine doctor and he needs a doctor," Kenniston repeated hopefully, to the Jovian. "Surely he wouldn't be foolish enough to shoot Ricky, even if I don't deliver the equipment." "Kenniston, don't fool yourself," warned Holk Or. "The chief said he'd shoot him if you weren't back with the stuff in two weeks, and shoot him he will. John Dark never breaks his word." That assurance sank the iron deeper into Kenniston's tormented soul. If that was true, and he knew in his heart it was, Ricky would die two days from now unless he'd delivered the repair-equipment to Dark. He mustn't _let_ Ricky die! Too much depended on his young brother's life. He must save Ricky even if it did mean the capture of Gloria and the others by the pirates. Better that they be held for ransom, than for Ricky to be killed! * * * * * Kenniston got to his feet, rigid with decision. "Then we've got to get out of here," he muttered. "We've got to escape and take word to Dark that the equipment is here." He continued quickly, "Holk, Dark's camp is only a few miles north of here. I spotted it as the _Sunsprite_ fell." Holk Or uttered an exclamation. "Why the devil didn't you tell me so! I figured it was on the other side of the asteroid, maybe, and that we'd never find it in the jungle even if we did get away." "It still won't be easy for us," Kenniston warned. "The Vestans may get us in the jungle between here and Dark's camp. And anyway, how can we get out of this cabin?" The big Jovian grinned. "That'll be easy. I'd have been out of here before now, only I was waiting for the ship to quiet down." Kenniston stared. "That door is bolted. And there's no tool or weapon in the cabin. They didn't forget a thing when they searched it!" Holk Or's grin deepened. "They forgot one thing. They forgot how strong a Jovian is on a little, weak-gravity asteroid like this!" CHAPTER V Night Attack Kenniston caught desperately at the hope implied by the Jovian's words. "What do you mean, Holk?" "I mean that I'm a hundred times stronger on this little asteroid than I am on my own world, Jupiter. I can break the bolt of that door any time I want to." "But there's an armed guard stationed outside it." "I know, and that's where you come in, Kenniston. When I rip the door open, you be ready to jump the guard."