There is a category of science romance out there, running parallel to science fiction. Neal Stephenson (Snow Crash)– a mathematician is one and Stephen Baxter is another. Putting the science back in fiction and taking us along with it into extraordinary scenarios with fantastic sweeps across history. I'd previously come across Stephen Baxter when reading Reality Dust - pure but very alternative and thoughtful science fiction. It was accompanied by an another long short story in the Futures compendium by Peter F Hamilton called 'Watching Trees Grow'. An amazing detective story spanning generations, about a Britain that has never left the Roman Empire. The Empire, now nearly thousand years old never vanished or collapsed, but redoubled it’s strength and held on, shaping all of history forever. But it's Stephen Baxter who has reached prominence with an extraordinary output of very intelligent science fiction and non-fiction too, with his engrossing book which traces the path not yet taken in Deep Future.

In Coalescent Baxter takes a different tack to Peter Hamilton. He sticks to reality. Rome collapses, a slow terrible implosion over hundreds of years as the Barbarians crush the life out of her. He now deals in historical fact. It’s Britain where Rome chooses to leave first, needing soldiers to defend Rome itself and Gaul. The population, led from Rome, is used to almost five hundred years of rule of law and prosperity. It cannot adjust, basic craftsmen skills seem to vanish, crime soars, most cannot believe the Emperor won’t be back. Order will be restored soon they hope. But this not science fiction; Baxter uses history to chart a novel that is quite wonderful in many respects, doing something that has long been needed and probably should become a textbook for all high schools across the land.

This is a story of a young girl Regina, a Roman British girl living in a villa with a lavish lifestyle and slaves who is suddenly abandoned by her mother Julia after her father accidentally kills himself. Regina is saved from ruin by her Grandfather, an old soldier and they flee to the safety of the wall. Regina’s story is central to this book, told over her lifespan and more, alternating with a more contemporary story of one George Poole searching for his long lost twin sister in Rome.

It is Regina’s story and the story of Britain suddenly engulfed by marauding Saxons and tribal chieftans trying to fill the gap that the absence of Roman garrison’s left behind.
The disintegration of Romano Britain is a huge hole in the teaching of history in schools. We know they came, what they did, when they left, but then history glazes over and becomes the ‘Dark Ages’. Baxter shines a very bright light indeed on those years and with subtle weaving entangles the adult Regina and her daughter Brica with the forever battling Artorius (Authur) and his mystic Myrddin (Merlin).
Baxter is no romantic. This shambolic, receding, violent Britain is full of rapists and killers and Regina has to learn to survive with cunning. Everything is crumbling. Eventually she finds a way to get herself and her reluctant daughter to Rome – ostensibly to find her mother, but also to seek revenge for the man who raped her when she was a beautiful seventeen and left her with child.

The sub-story of George Poole and his search for his sister is consumed by the growing story of ‘The Puissant Order of Holy Mary Queen of Virgins’. What is the connection between this secret convent in Rome and Regina’s story some sixteen centuries ago? Who is the mysterious Peter, friend of George's father who seems to appear in George's life without warning. What does he want from George?

Baxter has a vision and everything always comes back to Rome. Our modern history began there and it is still entwined in modern Europe. Indeed as I write this review, the Prime Minister of Italy is wrapping up six months of Presidency of Europe...and the President of Europe is in fact Romano Prodi. A lot of history between this and Regina’s tough ordeal to escape the creeping anarchy of fifth century Britain.

If you have ever asked yourself what happened to Britain when the Roman’s left, Coalescent wades in and fills the gap with wonderful, knowledgeable detail and something in you clicks. It must have been very much like this. Terrible, frightening, and you would have wanted to leave, follow the Romans, every night wish for them to come back and restore order, make the lights glow, water flow, mint the coins, make life work. But they had gone forever and yes, the dark ages came.

There is more, fantastic speculations, a young girl pregnant seeking freedom from a cult in Rome, the consequences of Regina’s legacy, the very future of mankind (or should that be womankind?) but the solid work here is recreating ancient Roman Britain and making everyone in it wholly believable.