‘What are you suggesting, Ari?’

He stepped closer to her, close enough to whisper. His face was hard, determined. She could smell boiled potatoes on his breath.

‘I’m suggesting that you and I should leave, now.’

She’d known this proposal was coming, yet her heart beat faster in response. ‘You’re talking about walking around the world. How—’

‘There may be ways to move more quickly. We can follow the trail Earthshine left.’ He pointed to the south-east. ‘It’s clearly visible. As for food, the store my wife has built up should be enough to sustain two.’

She grinned. ‘If stolen from her.’

‘If stolen, yes. The pressure suit she has preserved since she came through the Hatch from Mars would provide enough warmth for us, I believe – it is a thing of multiple layers, a thing designed for the harshness of Mars, which, even if separated out, could protect the two of us from the chill of this place, Per Ardua. There are tools, even weapons we could take.’

‘You would betray your wife?’

He shrugged. ‘I don’t think of it that way. Perhaps I am saving her from her own foolishness.’

‘Why should we do this?’

‘Because of the power this Earthshine pursues. Huge power, for those brave enough to grasp it. And worthy of it.’

She took a breath. ‘I feel – intoxicated. As I have ever since I started to uncover the strange mystery of this weaving of history. As if I was a child, plummeting down a hub-mountain glacier, out of control … We have both already walked away from our worlds, the very reality we knew, the history, the culture. Now here we are speaking of walking off into the dark. To our deaths – or unknowable glory.’ She looked at him. ‘Do you believe that when your history died, your gods died with it?’

He shrugged. ‘In the Christian tradition Jesu died and lived again. And in the tradition of my ancestors all the gods die, in a final war at the end of time, but another cycle begins.’

She nodded. ‘Our priests also talk of cycles of calamities that punctuate time. Perhaps on some deep level we, our ancestors, already knew this is true, this meddling by the Dreamers – whoever and whatever they are.’

‘So,’ he said, ‘will you come with me? Will you dare outlive your gods?’

Again, a breath. ‘When do we leave?’

CHAPTER 62

Titus Valerius, like Ari and Mardina and some of the others, had trouble adapting to the unending day of Proxima, Stef saw. The legionary found it difficult to structure his day, to sleep at night.

But he was in his element when it came to planning the trek to the antistellar. Even the betrayal of Ari and Inguill, who had taken so much of their stock and supplies with them, seemed to make no difference. He had a way of defeating problems just by waving them away.

‘So we must walk around this empty world. Pah! In my time I have participated in marches the length and breadth of Europa, Africa, Valhallas Inferior and Superior, and deep into Asia. Marches across hostile territories, into the frozen tundra where wild horsemen still lurk at the fringes of continent-spanning forests – and through Valhallan jungles where every leaf conceals a scorpion, where every shadow is likely to turn out to be a skinny little warrior with a blowpipe. What dangers do we face here? That we will trip over an earthworm? We will do this. I will lead you. We will march – and that is what the Roman army is for, above all else: marching. And if we have the spare energy I might have you all build a road while we’re at it, to ease the journey back. Why, I remember once on campaign—’

‘I’m enjoying this performance, Titus Valerius,’ Stef said with a grin, ‘but I don’t believe a word of it. For one thing, you’re not a surveyor, or a map-maker. There’s going to be nothing to wage war against on this trip. This will be an exercise in planning, Titus Valerius. In logistics. In survival.’

‘Survival? In a country where potatoes and beets grow wild? Why, it will be like a stroll through the estates of the Emperor Hadrian.’

She eyed him. ‘ColU, do you think he really understands what he’s taking on?’

The ColU sat on the ground beside the two of them, on a blanket spread out over the rusty dirt outside the shelter. Nearby, a low fire flickered, slowly boiling up another pot of water. ‘Titus Valerius is a brave man and we are lucky to have him at our side.’

Stef grinned. ‘Tactfully put.’

Titus Valerius scowled. ‘You tell me, then, star lady. Describe what it is about this journey that I don’t understand.’

‘I have done this before, Titus. To begin with, we are going to have to travel all the way around half a circumference of the world.’ With a broken stem she sketched a circle in the dirt, alongside a bold asterisk to which she pointed. ‘Here’s Proxima, the star. The circle is Per Ardua, the planet. Per Ardua keeps one face to the star at all times. So—’ She cut Per Ardua in half with a bold stroke, and scribbled over the hemisphere turned away from the star. ‘One half is always in daylight, one side is always in shadow – in endless night. The substellar, the point right under the star in the sky, is here.’ A thumbmark, on the world’s surface right beneath the asterisk. ‘Which is where we are. And that’s why the star is always directly over our heads. The antistellar is on the other side of the world.’ Another thumbmark. ‘It couldn’t be further away from this spot. And to travel there …’ She sketched a broken line stretching around half a circumference of her planet, from substellar to antistellar. ‘You see? The shortest possible distance we have to travel is half of a great circle – I mean, if we just head straight for the antistellar. That’s without detours, for such details as mountain ranges and oceans and impenetrable forests and ice caps. And the distance – ColU?’

‘Per Ardua is a little smaller than Earth. Around twelve thousand Roman miles.’

‘And, can you see, Titus? Half of that will be in daylight, and half in the dark. Six thousand miles across icebound lands and frozen oceans.’

‘In the dark?’ Titus was frowning now. ‘Where nothing will grow?’

‘Nothing but icicles on your beard. Exactly. Now do you see the challenge? We had a vehicle, motorised. It was still gruelling. Beth has been building a cart.’

Titus nodded. ‘Even if we completed it we would have to pull it. We have no engines, no draught animals. On the march, without vehicular transport, we expect to cover around twenty miles a day. So the journey would take us …’

Stef smiled. ‘Leave the mental arithmetic to me. Six hundred days. The best part of two years!’

‘And one of those years in the dark and cold, where nothing grows.’

She nodded. ‘It’s easy for us to express an ambition to reach the antistellar, Titus. But it may not be physically possible.’

He grinned. ‘You should be a centurion, Colonel Kalinski.’

‘Really?’

‘You never tell a Roman something isn’t possible. Romans know no limits.’

‘We have one advantage,’ the ColU said. ‘Ari and Inguill went ahead of us, as you say – and Earthshine went ahead of them. There ought to be a trail we can follow, easily visible on the surface of this static world. For, even if Ari and Inguill can have had little idea what they were walking into, Earthshine will have known what he was doing. I have no doubt he would have carried a full information store on Per Ardua, as explored by our people, Stef, in our home reality.’

Titus frowned. ‘You mean, he had maps of this world?’

‘More like a memory of maps.’

Titus pointed at the ColU. ‘And you, demon. Do you have a memory of such maps too?’

‘In my humble way, I was one of the pioneers of Per Ardua myself. And after humanity’s large-scale emigration to Per Ardua I made sure I kept track of the latest survey data, the exploration results. Yes, I “remember” the maps – at least of Per Ardua as it was.’