McCann went fishing. He found a spot where the bank curved, cupping a still, shallow patch of water, thick with reeds. He took leaves from a pretty little bush with white flowers shaped like bells. He scattered the flowers in the river, over the still spot.

Above the shallower water, by the reed-beds, dragonflies hovered and zigzagged, big scarlet creatures the size of small birds. Sometimes they dipped their abdomens into the river, breaking the sluggish, oily surface of the water. Perhaps they were laying eggs, Malenfant mused, wishing he knew more natural history; when you got down to it he knew very little about his own world, let alone this exotic new one.

To Malenfant’s surprise, fish started coming to the surface in front of McCann, their fins breaking the oily meniscus, their mouths popping. Evidently they couldn’t breathe. McCann, stocky, determined, splashed into the water and started grabbing the fish, holding their tails and slamming their heads against rocks on the bank.

Malenfant thought he saw something move through the water. He scrambled out fast.

It had been bigger than any fish, but not the distinctive shape of a croc or an alligator — something that must have been at least his size, and covered with sleek hair, like a seal. But neither of the others noticed anything, so he didn’t mention it.

They spent a day at the side of the river, and replenished their stock of fish, then moved on, heading steadily west.

By noon the following day they had come to a place which showed signs of habitation. A small beach close to the river was littered with blackened scars, perhaps the marks of hearths, and neat rings of holes showed in the ground. When Malenfant walked here his boots crunched over a litter of stone tools. Julia cowered, her huge arms wrapped around her torso. Malenfant asked, “What is it? A Runners” camp?”

McCann’s face was grim. “Runners are not so permanent as this — and nor do they make such structures. See these holes? They are for the wooden supports of tents and the like… But see the scattering of the fires, the heaps of discarded tools. Men do not conduct themselves so, Malenfant; we would build a single fire; we would take our tools with us. This is a Ham settlement — or was. And, look, the great thickness of the debris tells of a long occupation, which is of course typical of these dogged, infinitely patient Hams. But it was an occupation that was ended bloodily. Here, and here…” Stains on rocks, that might have been dried blood. “They are recent. It is the Zealots, Malenfant. We must be alert for their scouts.”

Julia was clearly distressed here. They moved on quickly.

After that, another day’s hike took them to the spot McCann had picked out as a possible crossing place. On the far side of the river, just as he had promised, the land was flatter and less rocky, and there was more life: a few shrubs, some straggling trees, even patches of green grass.

And, stretched between the banks, tied firmly to a rock on either side, there was a rope.

Malenfant and McCann inspected the rope dubiously. It seemed to be of vegetable fibre, woven tightly together into a thick cord.

McCann picked at the rope. “Look at this. I think this material has been worked by teeth.”

“It isn’t human, is it?”

McCann smiled. “Certainly this is not what our hands would make — but we have never observed the Hams or the Runners use ropes on such a scale, or to have the imaginative intellect to make a bridge — and still less the Elves or Nutcrackers.” He looked around coolly. “Perhaps there are others here, other pre-sapient types we have yet to encounter.”

Malenfant grunted. “Well, whoever they are, I’m glad they came this way.”

Malenfant crossed first. He went naked. He probed at the river bed with a wooden pole as he inched forward, and he dragged another rope, a length of “chute cord, tied around his waist. The water never came higher than his ribs.

Once he was across, he and McCann started to transfer their packs of clothes and food. They used a karabiner clip from Malenfant’s NASA jumpsuit to attach each pack to the ropes, then pulled at the “chute cord to jiggle the packs across.

Julia came next. She entered the water with a dogged determination that overcame her obvious reluctance — which wasn’t surprising, as her stocky frame was too densely packed for her to float; whatever else they were capable of, Neandertals couldn’t swim. McCann fixed a loop of cord around her waist and clipped her to the “chute line with the karabiner clip. Then he and Malenfant kept a tight hold of the “chute line as she crossed — though whether they could have retrieved her great weight from the water if something had gone wrong Malenfant wasn’t sure.

It took no more than an hour for them all to get across. They spread out their gear to dry, and rested. Cleansed by the water, lying on warm rocks, Malenfant found he enjoyed the touch of the sun on his face, the arid breeze that blew off the desert.

Julia grunted, pointing at the river. There were creatures in the water.

They were sleek swimmers, their hair long and slicked down, their bodies streamlined. Their hands and feet were clearly webbed — but those hands had five fingers, and the small-brained heads had recognizable eyes and noses and mouths. They were churning in the water, clambering over each other like mackerel in a net. Oblivious of Malenfant and the others, they seemed to be lunging at the sky, their round eyes shining.

They were hominids.

“Swimmers,” said McCann morosely. “Sometimes they’ll steal fish off your line… The Hams have stories of how a Swimmer will aid you if you get yourself into trouble in the water, but I’ve never observed such a thing. And, do you know, they appear to sleep with only one eye shut at a time; perhaps they need to keep conscious enough to control their breathing…”

Malenfant imagined a troupe of Australopithecines, perhaps, scooped from some quasi-African plain a couple of million years ago, and dumped by the merciless working of the electric-blue portals on an isolated outcrop of rock on some watery Earth. Ninety-nine out of a hundred such colonies would surely have starved quickly — even if they hadn’t drowned first. But a few survived, and learned to use the water, seeking fish and vegetation — and, in time, they left the land behind altogether…

And now here were their descendants, scooped up by another Wheel, stranded once again on the Red Moon.

Hominids like dolphins. How strange, Malenfant thought.

Something immense collided with the back of his head.

He was on the ground. He felt something pushing down on his back. A foot, maybe. One eye was pressed into the ground, but the other was exposed, and could see.

That fat new Earth still swam in the sky.

He heard a commotion. Maybe Julia was putting up a fight. A face — runtish, filthy — eclipsed the Banded Earth.

Once again the back of his head was struck, very hard, and he could think no more.

Shadow:

Shadow learned day by day how to live with these new people, here on the slope of the crater wall.

One morning she brought a bundle of ginger leaves she had collected from the forest. She approached the group of women that was, as usual, centred on Silverneck. She sat next to Silverneck, offering the leaves.

A woman called Hairless — left almost totally bald in her upper body by over grooming — immediately grabbed all the leaves. She passed some to Silverneck and the others. When Shadow tried to get back some of her leaves, Hairless slapped her away.

So Shadow came up behind Hairless and began to groom her. Though Hairless flinched away at first, she submitted.

But now Hairless spotted the baby, clinging to Shadow’s neck. She reached out and plucked the baby off Shadow, as if picking a fruit off a branch. Shadow did not resist. Hairless poked her finger in the baby’s mouth and fingered his genitals. The baby squirmed, his huge head lolling.