Robert Silverberg: Why?

We returned to the ship, entering the hatch a few feet from one of the vines that now encrusted it. Brock unsuited; the vine had left a red, raw line about his waist.

“The plant tried,” I said.

“To kill me?”

“No. To move on. To get going. To see what was behind the next hill.”

He frowned and said, “What are you talking about?”

“I’m not so sure, yet. I’m not good at seeing patterns. But it’s taking shape. I’m getting it now, Brock. I’m getting it all. I’m getting your answer!”

He massaged his stomach. “Go ahead,” he said. “Think it out loud.”

“I’m putting it together out of my dream and out of the things you said and out of the vines down there.” I walked slowly about the cabin. “Those plants—they’re stuck there, aren’t they? They grow in a certain place and that’s where they remain. Maybe they wiggle a little, and maybe they writhe, but that’s the size of it.”

“They can grow long.”

“Sure. But not infinitely long. They can’t grow long enough to reach another planet. They’re rooted, Brock. Their condition is permanently fixed. Brock, suppose those plants had brains?”

“I don’t think this has anything to do with—”

“It does,” I said. “Just assume those plants were intelligent. They want to go. They’re stuck. So one of them lashes out in fury at you. Jealous fury.”

He nodded, seeing it clearly now. “Sure. We don’t have roots. We can go places. We can visit a hundred sixty-four worlds and walk all over them.”

“That’s your answer, Brock. There’s the why you were looking for.” I took a deep breath. “You know why we go out to explore? Not because we’re running away. Not because there’s some inner compulsion driving us to coast from planet to planet. Uh-uh. It’s because we can do it. That’s all the why you need. We explore because it’s possible for us to explore.”

Some of the harshness faded from his face. “We’re special,” he said. “We can move. It’s the privilege of humanity. The thing that makes us us.”

I didn’t need to say any more. After eleven years, we don’t need to vocalize every thought. But we had it, now: the special uniqueness that those clutching vines down there envied so much. Motility.

We left Alphecca II finally, and moved on. We did the other worlds of the system and headed outward, far out this time, as much of a hop as we could make. And we moved on from there to the next sun, and from there to the next, and onward.

We took a souvenir with us from Alphecca II though. When we blasted off, the vine that had wrapped itself round the ship gripped us so tightly that it wasn’t shaken loose by the impact of blastoff. It remained hugging us as we thrust into space, dangling, roots and all. We finally got tired of looking at it, and Brock went out in a spacesuit to chop it away from the ship. He gave a push, imparted velocity to it, and the vine went drifting off sunward.

If had achieved its goal: it had left its home world. But it had died in the attempt. And that was the difference, we thought, all the difference in the universe, as we headed outward and outward, across the boundless gulfs to the next world we would visit.