Prince of Spires
Istar
I think that stems from NaNoWriMo, where a common (though not entirely serious) suggestion if you're stuck is that you should have ninja's attack.I was about to suggest a scene where one or several of the main characters are attacked by an unknown party. I've heard, but never tried, that kind of thing lends itself to getting a story/writing moving when you've stuck a wall.
And it should be viewed in that context. Some people who try NaNo will only aim for the 50k word count over all else. And when they get stuck, this is the tip they get. Basically, have something weird and exciting happen and run with that, even if it doesn't fit into your story. Anything goes, as long as it gets words on the page. It's a meme.