gravinul began to whine. Slowly, and quietly, like a big balloon, the Cosmicraft rose in the air.
"You're not going to turn on the rockets are you, Chief?" Mayer whispered.
"Certainly not. That would give us away for certain."
"Then how—"
Somewhat impatiently Brink said: "We're going to drift. And if you want to help, please quit asking foolish questions and pray that what little breeze there is stirring will carry us in the direction we want to go."
Whether it was because of Dan's prayers or just the good luck which usually assists those who strive valiantly to help themselves, the Cosmicraft began to float in the direction of the slavers' village. It was still too dark for the unaided eyes to distinguish objects clearly, but, thanks to the amplifying effects of the teleview, Captain Brink was able to set the craft down within a few meters of Lieutenant Sullivan's crouching form. He took care to have the hull of the spaceship between the village and the earthman.
Opening the airlock on the side of the ship which was turned away from the slavers' lair, Brink crawled stealthily out and guided Sullivan back to the Cosmicraft.
Within the protection of the invisible spaceship, Mayer embraced his pal warmly and said: "What was the trouble, Jimmy? Wasn't my imitation of the jackant's call good enough?"
"It was too darn good," Sullivan growled. "I couldn't distinguish your imitations from the genuine article. All night long, I've been chasing jackants all over the desert of Menfol!"
CHAPTER VI
The Wok Stables on Mars
CAPTAIN BRINK laughed uproariously but Mayer didn't even smile. In a voice that trembled with anxiety, he asked: "Tell me, Jimmy, did you find out anything?"
"What a question to ask the greatest cosmic sleuth in the Galactic System," Captain Brink chuckled. "Of course he found out something. Where is Miss Andersen, Jimmy?"
"She's somewhere near Vanrab. Zurek sold her to the dairy farm there. She probably is being forced to herd and milk woks."
"What on Mars are woks?" Mayer wanted to know.
"You tell him, Frank," Sullivan said. "I'm afraid I'm not much good at teaching kindergarten."
Captain Brink grinned and explained, "Wok is the Martian name for a species of dairy cattle. The brutes have never been thoroughly domesticated. They are half wild and unspeakably filthy. The work of herding them and milking them is so odious and so hazardous that no freeborn Martian can be hired to do it, no matter how high the wages may be. That is one reason why there is such an active market for slaves here on Mars. I understand that very few of the slaves who are forced to do this work live for more than a few months after they are drafted into the wok stables."
"How horrible!" Mayer exclaimed. Then, turning to Sullivan, he asked: "Are you sure Miss Andersen is at Vanrab?"
"Nothing is absolutely certain," Sullivan hedged. "But I'm sure enough to give you odds of ten to one if you
