A while back, I reviewed C.J. Sansom's first novel, Dissolution. Dark Fire is number two in this series of sixteenth-century crime novels, and it features the same lead character, the hunchback lawyer Matthew Shardlake. (A third book in the series is due next year.)
Sansom has a PhD in history, and has been a lawyer himself, so we can assume, I think, that the background is scholarly and authentic. In any case, it all seems to accord pretty well with what I remember of Tudor history from my own days as a student.
Dark Fire begins in 1540, three years after the first book. Henry VIII, though ailing, is still King. His first minister is still the arch-schemer, Thomas Cromwell. You had to be pretty quick on your feet to stay on top in Henry VIII's day, and Cromwell is quicker than most. To begin with anyway.
Shardlake finds himself defending a young girl on a murder charge. He is also sent on a mission for Cromwell. There are rumours that a government official has found the formula for Greek Fire, and Cromwell wants it, to strengthen his position with the King.
Greek Fire is mentioned by the ancients. It was a legendary substance which was used by the Byzantines to destroy Arab navies, but the Byzantines took such extreme precautions to keep its formula secret that eventually it was lost altogether. Shardlake has to find it again, while doing his best to prevent the execution of an innocent girl.
All in all the book is extremely well done. Some of the apparent creakiness of the plot turns out to be a bit of a double bluff, and the book rattles along quite painlessly for some 500 pages. I suspect that it helps if the reader has some background knowledge of Tudor England, but on the whole Sansom does a sound job of explaining what we need to know.