A crime from the past. A murder from the future.

DS Fiona Griffiths is bored. It's been months since she had a good corpse, let alone a decent murder to deal with. And then comes  news of a chilling  crime: not just a murder, but a decapitation, with an antique sword no less, and a murder scene laid out like a particularly gruesome crossword clue.

Gaynor Charteris was an archaeologist excavating a nearby iron-age site. Genial, respected, well-liked, it was hard to see why anyone would want to kill her. But as Fiona starts to investigate, she finds evidence of a crime that seems to have its origins in King Arthur's greatest battle - a crime so bizarre that getting her superiors to take it seriously is going to be a hell of a job. Especially since the crime hasn't yet been committed...