He walked unthinking until his legs throbbed and only then did he turn back. She was standing before the flyer and without raising her voice she said urgently, "There's a cat to my left! It's ready to spring."
Keith faded back several steps to get a view of the rear of the flyer, but he didn't dare risk hitting the ship. He could see the great beast moving, agonizingly slow, between the ten foot tree trunks. It was cat-like only in its tawny color and its crouching, ready-to-spring stalking. Its hairless head was long with a mouth that could open a foot wide; the rest of it, covered with stubby yellowish hair, seemed to be mostly long powerful legs built for leaping.
"I'll attract it over here," Keith called and stepped in front of the flyer.
"It won't change its prey," Marilyn answered. "Walk around behind me. As soon as I start to move it will jump. It will make two leaps; one to snatch me up and the next back to the trees. You'll have to be fast. If it misses me it will keep going and try again before you know it. I'll count three, take two steps away from the flyer and dive back under at three."
"Marilyn, stand still!" Keith shouted and was furious with himself. "I'll circle it."
"They're never alone," she said. She glanced at him then and said steadily, "one." She took a step away from the ship. "Two." Another step. "Three." She whirled and dived and the beast was in the air higher than Keith's head. It landed without stopping its forward momentum, its claws raking the spot where she had been the second before. Keith's gun fired and the creature crashed to the ground and moved no more. He ran to Marilyn and they climbed into the flyer before the cat's mate appeared at the edge of the woods. It sniffed their presence, hesitated momentarily, then seized its partner and dragged it off through the trees.
"It won't be back," Marilyn said calmly as it disappeared.
"Is that what your ... your people hunt?" Keith asked. He knew he wouldn't choose hunting the beasts for sport.
The boulders were left behind them that night and when they stopped they had crossed off another eight hundred fifty-one miles.