"Why, we all know about it, Cadet," said one of the first men Tom had
spoken to. "They're building receivers for cargo projectiles."

Tom gulped in surprise. "But how did you know?" he asked.

"Why, it's the only thing we've been talking about down at the garage
and at Sloppy Sam's, the jet-truckers hangout," replied the trucker.
"If this thing works, surface transportation will be finished."

"That's right," asserted another worker. "The whole industry will be
wiped out overnight. Nobody will have anything trucked any more.
Cargo'll be loaded into a projectile and shot off into space to a
passing freighter. Then the freighter carries it to its destination and
shoots it back down to a receiver."

"But how could you know all this?" asked Tom. "It is one of the Solar
Guard's most closely guarded secrets."

"It's all over Mars," declared the truck driver with a derisive laugh.
"Why, everybody knows it."

Suddenly one of the men yelled and pointed toward the fence. The jet
truck parked near the gate was rolling forward slowly. As Tom and the
men watched in horror, the giant vehicle crashed through the fence and
rolled into the restricted area, picking up speed.

In a flash Tom was inside the jet car, driving right through the hole in
the fence and speeding after the huge machine. Around him, guards were
running after the truck, shouting frantic warnings. Far ahead of him,
Tom saw Major Connel and Devers standing near several receivers lined up