A brilliant butterfly wandered past. The bird eyed it longingly and shivered into a rainbow of colors and darted away after it. "Come back!" Alsint shouted. He couldn't find them unaided. He had to have directions. The bird didn't return immediately. It played with the butterfly, flashing around it. Presently it tired of the sport and came back to the branch it had perched on. "Pretty bit of fluff," it said breathlessly. "Never mind that," said Alsint impatiently. "What about those people? Are they on this world?" "Oh, not here," said the bird. "A thousand planets away." Alsint groaned. The bird had been trained by a mad-man and was alternately raising his hopes and crushing them. "Not so," said the bird. "Here's history: a hundred and forty years ago, a couple, plant mechanics, were marooned--for the same reason." It flew from the perch and alighted on the plant machine, dipping its bill in a collecting tray. "Good stuff," it said, clattering its beak. * * * * * Alsint said nothing. It would tell him when it got ready, not before. "The plant machine's fine," said the bird. "It's a plant that's been taken apart. Can you put it back together?" "No more than it is," said Alsint. "No one can." "No one _you_ know," said the bird. "Here's more history: A hundred and forty years ago, this couple learned how to put it together--and it grew. A hundred and thirty years ago, they knew how to take an animal apart and keep it alive. A hundred and twenty years ago, they put the animal together and made it work in a new way." The bird sidled along the branch. "What's the difference between plant and animal?" it asked. There were countless differences, on any level Alsint wanted to think about. Cellular, organizational, whatever he named. But the bird had something simple in mind. "There are some plants which can move a little," Alsint said slowly. "And there are some animals that hardly move at all. But the real difference, if there is any, is motion." "Right. You'll get along fine," said the bird. "A hundred and twenty years ago, this couple--who by then had several children--put an animal together in a new way and got--pure motion." That was what had been puzzling him, and now he knew. "Teleports," he said. "They can teleport." "They can't," said the bird. "The mind's best for thinking--they say. And they've kept theirs uncluttered." The bird cocked a glittering eye. "I don't know about minds. I never had one." If they couldn't teleport, how had the bird got here? Alsint glanced at the bird. It wasn't perched on the plant machine and the wings were folded. Six feet off the ground it hovered, and not a breath of air stirring. "Behind you," said the bird. It didn't twitch a feather, but it was behind him now and he hadn't seen it move. "Teleports, yes," said the bird. "But they can't do it. We do it for them."