The Jupiter Theft

Jameson tried to focus again on the scampering aliens. It was hard, because they were never still. But then he saw what Dmitri was driving at. There was something odd about the placement of the Cygnans’ limbs.

There were two arms and four legs, or four arms and two legs, depending on how you looked at it. The middle pair functioned as either arms or legs, as the Cygnans’ whim dictated, so that they were continually shifting from centaurlike beings to four-armed bipeds. The three splayed fingers—or toes, if you preferred—were monkey-clever. All the joints bent in a rubbery curve, showing that evolution had provided a flexible alternative to the ball-and-socket joint.

But that wasn’t where the impression of strangeness came from.

The limb arrangement was asymmetrical. When you looked closely, you saw that the limbs were staggered—one placed noticeably forward of its mate on the opposite side. The middle pair in particular were lopsided. The attaching muscles on the middle limbs seemed to be placed higher, too—Jameson would have said they were rooted near the spine, except that there was no visible spine, just rippling bands of muscle ringing the creature’s body.

But once the eye got used to the asymmetry, there was no sense of wrongness. It was just … different.

“You see, the limbs have been displaced by evolution,” Dmitri said smugly. “Once there were two sets of three equidistant limbs or tentacles, like a double-ended hydra. But when it became a land creature, it had to choose an up and a down. They probably evolved the same way we did—took to the trees and came down again a few million years later. Only more deft and agile than us monkeys—with a choice of four hands for making tools or four legs for running away from their enemies.”

“Or chasing their prey,” Ruiz said sourly.

“Maybe. I’ll have to think about that dentition. Closest thing on Earth is a parasite—the lamprey. Rasps its way into a fish and sucks the juices.”

Jameson looked at the swarm outside and shuddered.

“Sounds unpleasant.”

Dmitri looked pleased with himself. “The only difference between a parasite and a predator is the size of the prey. A mosquito’s a parasite, a tiger’s a predator. When the predator gets too big for its victim, it tends to kill it, that’s all. Maybe these creatures’ ancestors ate on the run, like Cape hunting dogs.”

Hastily, Jameson changed the subject. “Wouldn’t the extra limbs just atrophy? Would evolution really displace them so drastically?”

“Sure,” Dmitri said. “Happens all the time. It doesn’t even have to wait for evolution. Take the asymmetrical sole. Flounders and other flatfish on Earth start life with the usual bilateral symmetry, with an eye on either side, like free-swimming fish. When they get older and decide to lie on one side, the eye on that side moves around to the other side of the head.”

Dmitri paused to snap a picture of a Cygnan applying some instrument to the bubble. Perhaps it was taking a picture of him.

“The clincher is those three eyes,” he said after a moment. “What’s one doing under the jaw? Simple! No jaw! It’s just learned to open like one. It started as three eyestalks around a central orifice.”

“So the creature’s’ just a glorified tube?” Ruiz ventured.

“Well … so are we. But yes.” He frowned. “I wonder what’s so important about the other end, that the Cygnans have to wrap them up like their heads.”

“What I’d like to know,” Jameson said, “is how they matched orbits with us. And just by eyeballing it, too!”

“And how do they manage without spacesuits?” Ruiz asked.

“Maybe a very tough outer cuticle, like nematodes,” Dmitri said.

“What are nematodes?”

“Most numerous animal on Earth. Little parasitic roundworms. Every species of higher plant or animal has at least one species of nematode living off it. Human beings have about fifty. Most you never notice. They can live in vacuum. Some even live in boiling water, in hot springs.”

“Where do you get all these nasty, facts?” Ruiz said.

“My specialty was parasitology,” Dmitri said with a self-satisfied smirk. “Good training for an exobiologist. You’d be surprised at some of the adaptations—”

“Later,” Ruiz said hastily. He turned to Jameson. “Tod my boy, what are we going to do about our visitors? Can we let a delegation of them inside for a talk?”

“Some of us may go outside,” Jameson said. “The skipper’s talking it over with Captain Hsieh now.”

At that moment a mild sensation washed through his body, as if he were on a descending elevator. He’d suddenly lost his one percent of weight. Ruiz noticed it too. He looked up questioningly. Only Dmitri seemed oblivious. He was opening his mouth for another little lecture, his slippers hooked into the fuzzy surface of the deck.

“Drive’s off,” Jameson said. “That’s odd. We still have another couple of hours of braking to do.”

“Mister Jameson!” Boyle was bawling his name from the control balcony.