They cleared the last of the thick brush, and then the car slid unerringly up the cracked slope of the hill, its pistons barely raising dust. Alex could tell from the eerie smoothness of the ride that the car never skipped, and never skidded. The intelligent pads at the base of each spoke contacted the earth with a dainty and tentative touch. Then the pistons set themselves firmly and punched up against the diamond hub, lifting the car in repeated, near-silent, precise staccato, faster than any human eye or ear could follow. It was like riding the back of a liquefied cheetah.