But, looking back now, I can better appreciate what Rowling did. She had millions of people worried that Harry might actually die. She had the knife to his throat, and for lots of people, it was entirely possible she might use it.
I love a good action scene -- truly, I do -- but that's a lot different than actually exposing your characters to mortal danger (or psychological or emotional danger). I wonder if sometimes, writers head into action scenes already emotionally knowing their character will survive. That's risky, because it bleeds into the emotional arc of the scene. The danger isn't felt as deeply as it could be because the conclusion is foregone. The lows aren't as low, so the highs can't be as high. In other words, we're leaving something on the table. The stakes aren't as high as they could be, aren't even as high as they appear to be.
Maybe next time I write an action scene, I'll kill off the main character. Just to scare myself silly, and so can I really feel it, so I know intimately what kind of fate I'm avoiding. I can always save him on the rewrite.