I was listening to Steven Moffat talk on Doctor Who Confidential about the importance of keeping the surprises in Doctor Who a secret, something he's striven very hard to do (unlike the producers of soap operas who trail major plot developments weeks in advance through the media). It's obviously no mean thing to achieve when you're producing something on the scale of one of the Beeb's top-rated dramas, but it can prove a challenge for us jobbing writers too.
These days I often get to write the blurbs for my novels myself, or at least the first version thereof. Writing blurbs is a challenge in and of itself but at least I retain control over what's revealed and what isn't. You want to dangle enough carrots to get readers to want to part with their cash to read the book in the first place but you don't want to reveal the final twist that comes right at the end.
However, in the past, I didn't write my own blurbs and this resulted in one of the biggest cock-ups, in terms of revealing the ending, I've ever had. Magestorm was my third novel for the Black Library, written to tie into the Storm of Chaos campaign as well as Dan Abnett's Riders of the Dead. That proved a challenge in itself, but I also had to base it on the War Cry CCG, including various characters from that game in my novel.
I have to confess, it's not my best work, but the blurb on the back of the book certainly didn't help when readers actually read the book because it gave away a major plot reveal that only came in the penultimate chapter (or thereabouts). And now it's happened again.
Sir Dagobert's Last Battle will be available to read as part of Hammer & Bolter Issue 9. It's full of twists and turns and (hopefully) unexpected reveals - except that one of them has already been given away in the single sentence that's promoting it on the Black Library website. So, if you're planning on reading my latest Warhammer short story, by all means follow this link and click the pre-order button, but please don't read the write up of the story as you do so.