Some documents change history. This one is worth killing for.
Dr Sarah Walmsley expected the dig at Tonbridge Castle to yield pottery shards and postholes. Instead she finds a hidden chamber, a pendant that shouldn't exist - and the truth about her father's death. James Walmsley wasn't the victim of an accident. He was murdered for what he knew: that history itself can be rewritten, and that someone is doing exactly that.
The Restoration Society has spent centuries perfecting the art of correcting the past. Their next target is the foundation stone of English liberty - Magna Carta, Runnymede, 1215. If the charter falls, democracy dies in its cradle.
With her sister Lily and a hastily assembled team, Sarah must follow her father's trail eight hundred years back - into a world of blades, barons and treachery, where one wrong word can unmake the future. But the Society is already there. And winning, Sarah is about to learn, can be more dangerous than losing.
The first novel in The Divergence Engine, a five-book thriller series where the past is a battlefield. Perfect for readers of The Chronicles of St Mary's, Timeline and The Anubis Gates.