‘Utterly unique . . . A masterpiece’ The Daily Mail ‘Stunning . . . Brilliantly original’ The Guardian London is built from concrete, steel and the creative urge. Old technology gives way to the new. Progress is inevitable – but is it more fragile than its inhabitants realize? A strange anomaly is uncovered in the new top-secret Crossrail extension being built under Buckingham Palace. It is an archaeological puzzle, one that may transform our understanding of history – and the origins of London itself. And if our modern world falls, we may have to turn to the technology of the past in order to save our future.