Vivian Onim's answer to What Harry Potter subplot dead end do you wish JKR had concluded in her books to your great irritation? - Quora
(What a horrendously long title! It wouldn't even let me post at first. Anyway you should go read the answer, it's great. This is me using the Signal Boost bookmarklet btw, a nice little tool.)
THE BRAIN SCARS OH MY GOD THOSE BLOODY BRAIN SCARS -
If there is a plot point that caused me endless frustration it's this one.
Picture it: our main characters break into a super-secret government facility, in which are contained Things That Mankind Was Not Meant To Know and lots of probably unethical experiments that may or may not involve human experimentation… after all, every government has skeletons in their closets, they just gotta find a big enough closet to hide'em.
Our brave - and stupid - heroes get inside, but to everyone's horror and nobody's surprise, the bad guys were waiting for them!
Begin chase scene and fighting, drama happens, the party starts dwindling -
Then suddenly, GASP...
(What a horrendously long title! It wouldn't even let me post at first. Anyway you should go read the answer, it's great. This is me using the Signal Boost bookmarklet btw, a nice little tool.)