The Long War

heading north, those to the left heading south. The biggest of them were huge , like tanks indeed, or even bigger, with shells the size of small houses that were battered, scarred – some had birds’ nests built into folds and cracks on the shells, and Roberta wondered if those passengers had some kind of symbiotic relationship with their hosts. But she could immediately see that the tortoises came in a spectrum of all sizes scaling down from the big monsters, to ‘giants’ that wouldn’t have looked out of place on the Galapagos Islands, to miniature sorts like the pets Roberta had seen people keep, even dwarf kinds she could have held in her hand. The smaller ones ran around the tree-trunk legs of the big lumbering monsters. The noise was cacophonous, from the squeaks of the smallest to great blasts from the titans, like the fog horns of supertankers.
    Yue-Sai pointed out the little ones, and laughed. ‘The babies are so cute.’
    Roberta shook her head. ‘They may not be infants at all. There are probably many species mixed up in there.’
    ‘I suppose you are right. And I suppose we will never know what is what.’ She sighed. ‘So many worlds. So few scholars to study them. If only we had laboratories to produce self-replicating scientists, to explore all the worlds. Ah, but we do! They’re called university campuses.’
    Roberta smiled uncertainly.
    Yue-Sai said, ‘You don’t get the joke? I suppose it was a little laborious. But is my English so bad?’
    ‘It’s not that. It’s just that, Jacques and other teachers tell me, I am too smart for most jokes.’
    ‘Really,’ Yue-Sai said, straight-faced.
    ‘There is an element of deception in many jokes, and then a reveal, of a truth which is surprising. I spot the deception too early. Which is why the comedy I prefer is—’
    ‘Slapstick. Anarchic humour. Those Buster Keaton films you watch. I understand now. Anyhow, all these worlds—’
    ‘And all these tortoises . . .!’
    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