The Long War

They had discovered a whole sheaf of worlds of this kind. The further they got from the Datum, the stranger the worlds they encountered, the stranger the ecologies. In a way, tortoise worlds might have been anticipated. On the Datum the tortoise-turtle body plan was an ancient, ubiquitous and very successful one. Why shouldn’t there have been worlds where tortoise lineages dominated?

“In many worlds,” Yue-Sai said, “even on the Datum, you’ll find tortoises behaving like this. Forming lines to get to waterholes, like the lake higher up this valley. Drinking their fill, enough to last months.”

“But not a line a hundred miles long.”

“No,” said Yue-Sai. “And not a line running on what looks like a road, with a metalled surface.” Not that they’d been able to get close enough to check that out. “And not a line with traffic police…”

These were individuals about the size of Galapagos giants. They stood on raised islands in the middle of the two-way flow, or in bays cut into the valley walls. Some of them had belts wrapped around their shells, with pockets, pouches. They even had tools, like whips that cracked occasionally, and things that looked like simple horns to Roberta, to amplify their calls. The function of these individuals was clear: to keep the tremendous flow moving peaceably. They would dive in, horns blaring, if there was a clash, or the two-way lanes got mixed up, or a little one fell under the feet of the giants. Somehow, amid a chaotic clatter of shells, everything got sorted out.

“We might have expected intelligence,” said Yue-Sai. “I have been studying. On the Datum, people learned that tortoises could solve mazes. At least, that was when people gave tortoises a chance to solve mazes, as opposed to eating them, or stifling them in ‘hibernation boxes’. Perhaps there are great cities elsewhere on this world. Tortoise armies. Tortoise colleges… That thought makes me want to laugh, but I’m not sure why.”

“I don’t believe we’ll find anything too advanced,” Roberta said. “Not locally.”

“Why not?”

“Look at the wardens’ tools. They have similar functions, obviously, but differ in detail. See? The stone here is shaped differently from there. The braiding on the whip handle—”

“So what?”

“Tortoise culture must be different from ours,” Roberta said. “Their reproduction patterns are different. If you are a tortoise you emerged from one of hundreds of eggs; you don’t know your parents; you received no parental care. Their young may not be guided through family backgrounds and formal education as we are. Perhaps they compete for a right to live, and part of that competition is learning how to make tools. But that means every generation must more or less reinvent the culture from scratch.”

“Hmm. Thus limiting their overall progress, generation to generation. Maybe. That is a lot of supposition based on just a little data.”

Roberta had learned not to say things like It’s too beautiful a theory not to be true. Once Jacques Montecute, overstressed, had told her that she should have the slogan “Nobody Likes a Smart Alec” tattooed to her forehead in reverse, so she could be reminded of it every morning in the bathroom mirror. She contented herself with saying, “It does fit with the likely physiology, and the evidence of the non-uniformity of the tools. But, yes, the theory needs more testing. It would be interesting to know what’s going on nearer the equator in this world.”

Yue-Sai did a double take. “Why so?”

“Because those tortoises that solved the mazes back on the Datum were allowed to do so in warm conditions. Tortoises are cold-blooded; they shut down in the cold, to some extent.”

“Oh. So maybe the behaviour we’re witnessing here, in the cold, is—”

“Limited by temperature. They may be achieving much more in warmer latitudes. Do you think Captain Chen would sanction a journey south, towards the equator?”

“And risk getting shot down by some super-tortoise? I do not think so.” Yue-Sai packed away her equipment. “Time to get back to the ship.”

Before they left, Roberta glanced across the valley, to the far wall where erosion had exposed the strata of the local sedimentary rocks. She could clearly see a marine deposit, a chalky layer embedded with flints, below a bed of gravel, and then above that a few yards of peat, under the mossy ground surface. She could read the geology. This region, now elevated, had once been under the sea. Later, ice had come and gone, leaving behind the gravel, and then the peat had been laid down over millennia of temperate climates… This world, like all other worlds, had a story of its own, a story billions of years deep and probably not quite like any other in the Long Earth ensemble. A story that probably nobody would ever get around to unravelling, and all she would take away from this place was a few snapshots of tortoises.

She could only turn away.