They must have been spectacular eruptions. Thick, dense rock near the surface appeared to have blocked the magma flows, bottling up increasing pressure before yielding explosively like a champagne cork flying out of a bottle. On Earth, such stratovolcanoes — like Mount Fuji, Mount Rainier — could eject debris miles into the air. On the Moon the volcanoes had blown debris clear of the planet altogether. Meanwhile vast quantities of dust and gases had been pumped into the atmosphere, to spread in thick bands around much of the Moon’s middle latitudes.

There was a great deal you could tell about the Red Moon, even from a quarter million miles, with telescopes and spectrometers and radar, as the two hemispheres conveniently turned themselves up for inspection. For instance, those oceans really were water. The temperature range was right — as you’d expect since the Moon shared Earth’s orbit around the sun — and examination of the visible and infra-red spectra showed that the clouds” caps were made of water vapour, just the right amount to have evaporated off the oceans.

The Red Moon’s surface gravity was some two-thirds Earth’s — a lot more than Luna’s, and, crucially, enough for this miniature planet to have retained all the essential ingredients of an Earthlike atmosphere: oxygen, nitrogen, carbon, water vapour, carbon dioxide — unlike poor barren Luna. So the Red Moon had water oceans and a nitrogen-oxygen atmosphere.

Already the study of the Red Moon had revolutionized the young science of planetology. With a quarter of Earth’s mass — but four times the mass of Mars, some twenty times the mass of Luna — the Red Moon was a planet in its own right, intermediate in size between the Solar System’s small and large denizens, and so a good test-bed for various theories of planetary formation and evolution.

It differed in key ways from Earth. Because it was so much smaller, it must have started its formation (wherever that had occurred) with a much smaller supply of heat energy than Earth. And that inner heat had been rapidly dissipated through its surface.

Like a shrivelled orange, the Red Moon’s rind was thick. Probably aeons ago, the tectonic plates fused, and continents no longer slid over its face. There was no continental drift, no tectonic cycling, no oceanic ridges. Unlike Earth, the Moon’s uncycled surface was very ancient; and that was why the interior of the continent bore those huge eroded craters, the scars left by immense impacts long ago.

And that was why the Bullseye was so vast. The huge shield mountain had probably formed over a fountain of magma erupting through a flaw in the crust layers. The crust beneath it must have been held in place over the flaw for hundreds of millions of years — so it more resembled Mars’s Olympus Mons than, say, Earth’s Hawaiian islands.

But there was more than geology up there. On the Red Moon, it appeared, there was life.

The air was Earthlike, containing around a sixth oxygen — a smaller proportion than Earth’s atmosphere, but difficult to explain away by non-living processes. It hadn’t taken long to establish that the green-grey pigment that stained the fringes of the supercontment and its wider river valleys, as well as the shallower sections of the world ocean, was chlorophyll, the green of plants. There were other fingerprints of a living world: an excess of methane in the air, for example, put there perhaps by bacteria in bogs, or burning vegetation, or even the farts of Moon-calves. Though some scientists remained sceptical and though nobody could say for sure if the Red Moon harboured anything like bogs or bacteria or cows — most people seemed to concur that there was indeed life on the Red Moon, life of some sort.

But was there intelligence?

Nobody had detected any structured radio signals. There had been no response to various efforts to signal to the Red Moon using radio and TV and laser, not to mention a few wacko methods, like the cutting of a huge right-angled triangle of ditches into the Saharan desert filled with burning oil.

But what were the mysterious lights that flickered over the night lands? Most observers claimed they were forest fires caused by lightning or drought. Perhaps, perhaps not. Could the streaming “wakes” sometimes visible on the great oceans be the wakes of ships, or were they simply peculiar meteorological features? And what about the geometrical traces — circles, rectangles, straight lines — that some observers claimed to have made out in clearings along the coasts and river valleys of the Red Moon’s single huge continent? What were they but evidence of intelligence?

And if any of these signs were artificial, what kind of being might live up there to make them?

Malenfant was willing to admit that one manned expedition could do little to probe the mysteries of a world with fully half the surface area of Earth. But there were mysteries that no amount of remote viewing could unravel. The fact was, the most powerful telescope could not resolve an individual human being up there.

Malenfant was never going to find Emma by staring up from Earth.

But at this time of crisis, nobody wanted to see Malenfant’s drawings of rocket boosters and gliding spaceships.

Of course there was the question of resources, of priorities. But Malenfant suspected that people were shying away from dealing with the most fundamental issue here: the existence of the Red Moon itself. It was just too big, too huge, impossible to rationalize or grasp or extrapolate. The Wheel was different. A blue circle in the air, a magic doorway? Yes, we can imagine ways we might do that, even if we can’t think why we should. Peculiar-looking human beings falling out of the air? Yes, we know about the plasticity of the genome; we can even imagine time travel, the retrieval of our flat-browed ancestors. But what kind of power hangs a new Moon in our sky?

He didn’t last long in the water; it was too cold. He took a few brisk strokes until the water was shallow enough for him to walk. He splashed out of the surf, shivering, briskly dried himself on his shirt, and began to pull on his pants.

There was somebody standing beside the beached berg fragment, just a slim shadow in the grey dawn light, watching him.

Fire:

Maxie is running around Fire’s feet. “Hide and seek. Hide and seek, Fire. Hide and seek.”

Fire stares at Maxie. To him the boy is a blur of movement and noise, unpredictable, incomprehensible, fascinating.

Maxie has leaves on his head. They flutter away as he runs. Sally puts them back on. “No, Maxie,” she says. “Be careful of the sun.”

“Hide and seek, hide and seek.” He stands still. His hands cover his eyes. “Hands, Fire, eyes, Fire.” His hands cover his eyes.

Fire puts his hands over his eyes. It is dark. The night is dark. He starts to feel sleepy.

Maxie calls, “Eight nine ten ready! Fire Fire Fire!”

Fire lowers his hands. It is not night. The sunlight is bright. The world is red and green and blue. He blinks.

Maxie has gone away.

Fire sees Sing on her bower of leaves. He walks towards her. He has forgotten Maxie.

Maxie is at his feet. “Here I am, here I am!” Maxie stamps his foot. Red dust rises and sticks to Maxie’s white flesh. “You have to try, you silly. You have to play it right. Try again, try again. Eyes, Fire, hands. Fire.” He covers his eyes.

As the sun climbs into the sky, the game goes on. Every time Maxie disappears Fire forgets about him. Every time he comes back Fire is surprised to see him.

Fire grows hungry. Fire thinks of himself in the forest, eating nuts and berries and leaves. Fire lopes towards the forest.

“Come back, come back, you nasty!” Maxie falls to the dirt and howls.

Emma comes running to Fire. “Fire, are you going to the forest? Can I come with you?”