‘Komm! Hermann, komm!’

The feathered beast hung its head and loped away.

The woman approached the new arrivals, her hand resting on a weapon at her belt. She wore a uniform of jet black, with lightning flashes at the collar and sleeves. She wore no hat, and her grey hair was pulled back tightly from her forehead. She was old, Mardina saw immediately, though she walked confidently enough. And she looked hauntingly familiar.

‘Wie heißen Sie?’

Mardina, clutching Gwen, murmured to Chu, ‘Put your dagger away …’

‘Was machen Sie hier?’

Mardina stared at the woman. It was Stef Kalinski. Or Penny. Or, Mardina thought wildly, another Kalinski twin. ‘You!’

But the woman had eyes only for Chu. Just as Mardina had recognised her, now she, evidently, recognised Chu.

The woman dropped to one knee and hung her head. ‘Verzeihung, Eure Exzellenz!’

Chu just stared back, astonished.

Always another door, Mardina thought. Just as grandfather Yuri had said. ‘Let me handle this.’ She handed the baby to Chu, spread her hands, and walked forward, towards the kneeling stranger.

EPIGRAPH 4

In the hearts of a hundred billion worlds

Across a trillion dying realities in a lethal multiverse –

In the chthonic silence –

All that could have been done had been done.

In peace and satisfaction, minds diffuse and antique submitted to the End Time.

AFTERWORD

Since the publication of Proxima the scientific study of the potential habitability of tidally locked planets of red dwarf stars has continued. For example, the first three-dimensional atmospheric model of a world like Per Ardua was published in 2013 (D. Abbot et al, Astrophysical Journal Letters, vol. 771, L45).

A recent reference on the Roman Empire and its provinces is Roman Britain by Patricia Southern (Amberley, 2011). Roman dates given here are based on the system used from the later republic, when scholars counted the years from the founding of the city of Rome. The founding date used here is that given by Varro, but other scholars differed. ‘AUC’ is an abbreviation for ab urbe condita, ‘from the founding of the city’.

A recent if speculative reference on Celtic culture is Graham Robb’s The Ancient Paths (Picador, 2013). A useful recent reference on the Incas is Kim MacQuarrie’s The Last Days of the Incas (Simon & Schuster, 2007). Recent evidence on the Incas’ use of child sacrifice is given in Current World Archaeology no. 61, 2013. Anglicised spellings of Quechua terms vary; I have aimed primarily for clarity.

There was a devastating volcanic eruption in the year 1258, the eruption of the millennium and with global effects (see, for example, Current Archaeology, September 2012). Its location has quite recently been identified as Indonesia.

The ‘gravity train’ was devised in the seventeenth century by British scientist Robert Hooke, who presented the idea in a letter to Isaac Newton. The idea has been seriously presented a few times, such as to the Paris Academy of Sciences in the nineteenth century.

There is a large literature on the feasibility of space colonies. The Inca design depicted here is extrapolated from the work of O’Neill in the 1970s (G. K. O’Neill, The High Frontier, William Morrow, 1976). The use of modern materials and techniques to build very large structures has been explored, for example, by T. McKendree (‘Implications of Molecular Nanotechnology Technical Performance Parameters on Previously Defined Space System Architectures’, Turning Goals into Reality, NASA, 2000, http://www.zyvex.com/nanotech/nano4/mckendreePaper.html#RTFToC17).

The far future of the Alpha Centauri system has been described by Martin Beech (‘The Far Distant Future of Alpha Centauri’, Journal of the British Interplanetary Society, vol. 64, pp.387–95, 2011). A recent reference on natural panspermia is ‘Dynamics of Escaping Earth Ejecta and their Collision Probability with Different Solar System Bodies’ by M. Reyes-Ruiz et al (2011, arXiv:1108.3375v1).

Recent references on the collective behaviour of bacteria are relevant essays in Chimeras and Consciousness by Lynn Margolis et al (MIT Press, 2011). New extensive surveys of the ‘dark energy biosphere’, life deep underground, were reported in June 2014 at a conference at the University of California, Berkeley (New Scientist, 21 June 2014).

The ‘Doomsday Argument’, developed by Brandon Carter and others and referred to by Stef Kalinski in Chapter 67 – one version of which suggests that our future may not be infinite but of the same order of magnitude of our past – is explored in John Leslie’s The End of the World (Routledge, 1996). The alarming suggestion that our universe may have only a relatively short future because of our existence within a ‘multiverse’, an ensemble of universes, was set out in 2010 in a paper called ‘Eternal Inflation Predicts that Time Will End’, by Raphael Bousso of the University of California, Berkeley, and others (arXiv:1009.4698v1). A recent background work on the subject is Universe or Multiverse? ed. Bernard Carr (Cambridge University Press, 2007). The physical consequences of the end-time event as depicted here were suggested by Igor Smolyaninov of the University of Maryland and others (‘Hyperbolic Metamaterial Interfaces: Hawking Radiation from Rindler Horizons and the “end of time” ’, 2011, arXiv:1107.4053v1). The science of ripples-in-spacetime faster-than-light warps derives from a seminal paper by Miguel Alcubierre (Classical and Quantum Gravity vol. 11, L73–L77, 1994). The detection of primordial gravitation waves, by the BICEP2 telescope in Antarctica, was first announced in March 2014 (New Scientist, 22 March 2014). For an exploration of how to turn an Einsteinian wormhole into a time machine, see my own novel Timelike Infinity, in Xeelee: An Omnibus (Gollancz, 2010).

Once again I’m deeply grateful to Prof. Adam Roberts for help with my Latin homework.

Any errors or inaccuracies are of course my sole responsibility.

Stephen Baxter

Northumberland

July 2014

ALSO BY STEPHEN BAXTER FROM GOLLANCZ:

NON-FICTION

Deep Future

The Science of Avatar

FICTION

Mammoth

Longtusk

Icebones

Behemoth

Reality Dust

Evolution

Flood

Ark

Proxima

Xeelee: An Omnibus

NORTHLAND

Stone Spring

Bronze Summer

Iron Winter

THE WEB

Gulliverzone

Webcrash

DESTINY’S CHILDREN

Coalescent

Exultant

Transcendent

Resplendent

A TIME ODYSSEY (with Arthur C. Clarke)

Time’s Eye

Sunstorm

Firstborn

TIME’S TAPESTRY

Emperor

Conqueror

Navigator

Weaver

A Gollancz eBook

Copyright © Stephen Baxter 2014

All rights reserved.