TL;DR: If your blurb spoils the plot of your book then you’re doing it wrong.
I’m reading The Pendragon Protocol by Philip Purser-Hallard. It’s a really good book that manages to go far beyond what could have been a really cheesy premise. I’ll talk about that in a later post. What follows is the blurb from the back cover:
The Circle are the modern-day successors of the Knights of the Round Table. Armed with the latest military hardware and operating from a hidden fortress on the South Bank, they protect 21st-century Britain from certain very specific threats – criminals who, like the Circle’s own Knights, have characters from Arthurian legend living inside their heads.
Jory Taylor, the Knight bearing the device of Sir Gawain, has grappled on the Circle’s behalf with mercenaries, serial killers and far-right terrorist cells. However, when he is captured by Gawain’s traditional enemy the Green Knight, he discovers a new side to the myths he lives by – one which, as he learns more about this clandestine world, becomes both threateningly personal and terrifyingly political.
The Green Knight is first mentioned on page 73 and we find out that Jory’s device is sir Gawain on page 77. The prose treats it as a big reveal, but, because of the blurb, it isn’t. I know when I was reading that chapter it would have been with far greater anticipation had Jory’s device not already been known.
Jory is finally captured on page 138. All of the plot up until that point has been setup. It’s pretty good setup, but really we’ve just been waiting for this point in the book because this is where the blurb suggests that true story begins.
This is a 350 page book.
I know that we live in the future, where movie trailers tell us pretty much the entire plot, but books are not movies. They require a far greater investment of time and effort. It might take me a couple of evenings just to get to the point where I pass the events of a blurb. That’s ridiculous. No one likes a spoiler.
A blurb should give you an idea of a book’s tone and suggest what kind of content it might contain. It should in no way be specific as to what actually happens.