The Secrets of Life and Death tells two stories - one set in current day England where Jack Hammond struggles to save a young girl's life through unconventional means. The other is set in 16th century Poland, following the equally unconventional exploits of John Dee and Edward Kelley as they're called in to aid the notorious Countess Elizabeth Bathory (you know the one- she purportedly bathed in the blood of virgins...she's a pretty evil lady). As you might guess, Dee and Kelley's experiments with dark magic are intimately related to Jack and Sadie's struggle for life (or, rather, more borrowed time).
This seems like something I would automatically love, but I was left with lukewarm feelings. The characters never quite got there and the dual story lines just felt a bit disjointed. Every time I started getting into the action of one story line, I was yanked out and had to reacclimate. There are ways to pull this off, but it's tricky. The two stories felt a little out of step with each other.
I'd still recommend picking this up. It was a fun read and it's a story I've found myself thinking about over the past few days since I finished it. If nothing else, read it so you know what's going on when you read the second one (
The Secrets of Blood and Bone), which was much better.