 Why is the rumor that Martians can read minds especially scary to Ben?
With never a moment to rest, the pursuit through space felt like a game of hounds and hares ... or was it follow the leader? The place was like an evil caldron steaming with a brew whose ingredients had been culled from the back corners of three planets. Most of the big room lay obscured behind a shimmering veil of tobacco smoke and the sweet, heavy fumes of Martian Devil's Egg. Several times, Ben glimpsed the bulky figures of CO 2 -breathing Venusians, the first he'd ever seen. Even when they played an Earth tune, it still seemed a song of old Mars, charged with echoes of lost voices and forgotten grandeur. Again, its face would be a pop-eyed mask of surprise as Ben's fist thudded into its jaw. He was three months out of the Academy at White Sands and the shining uniform was like a key to all the mysteries of the Universe. At the age of five—perhaps in order to dull the memory of his parents' death in a recent strato-jet crash—he'd spent hours watching the night sky for streaking flame-tails of Moon rockets. At fourteen, he'd converted an abandoned shed on the government boarding-school grounds to a retreat which housed his collection of astronomy and rocketry books. There, among the grizzled veterans of the old Moon Patrol, he'd found friends who understood his dream and who later recommended his appointment to the U. S. Academy for the Conquest of Space. And a month ago, he'd signed aboard the Odyssey —the first ship, it was rumored, equipped to venture as far as the asteroids and perhaps beyond. Under interplanetary law, that would mean ten years in prison and a dishonorable discharge. They don't want new men over thirty-four for officers on rockets or even for third-class jet-men on beat-up freighters—they don't want convicted killers. Or— There were old wives' tales of a group of renegade spacemen who operated from the Solar System's frontiers. And whereas no legally recognized ship had ventured past Mars, the souped-up renegade rigs had supposedly hit the asteroids. So , Ben reflected, you can take a beer-and-pretzels tale seriously. You can try to stay in space, even if you exile yourself from Earth. After all, was it right for a single second, a single insignificant second, to destroy a man's life and his dream? So now he sat searching for a perhaps nonexistent red-bearded giant, and hoping and doubting and fearing, all at once.
 If they can, they definitely know he's guilty of what he's done.
 If they can, they definitely know he's guilty of what he's done.  It would mean that Martians are fully aware of what Earth people are thinking, and manipulating them.  If they can, he's uncomfortable with the notion that they can read his thoughts.  Not being able to confirm if it's true or not makes Ben wary of interacting with any of them.