I’ve commented previously about characters who act stupidly for no other reason than to further the plot, but occasionally I come across something slightly different. There’s a good example of this in Harry Potter and the Chamber of Secrets when Dumbledore is talking to Harry after the first couple of attacks and asks if Harry has anything to tell him. Harry declines.
While I don’t feel that Harry is being unusually stupid per se, I don’t understand why he doesn’t mention hearing the voice in the walls. I get that he doesn’t want to mention the trio’s clandestine potion-making. I can accept that he doesn’t want to accuse Malfoy without any evidence (though he’s certainly keen to later in the series). It makes sense that he’s not ready to talk about being upset at everyone assuming he’s to blame (he is fairly introverted, after all). I think the reason it feels a little off is that it’s not really well-justified – the author felt the need to remind the reader of Ron’s earlier comment about hearing voices. Even the conversation where Ron delivers this piece of advice is unusual in that Hermione (normally the one saying they should tell a teacher) being completely silent. Re-reading the scene, I had to check back and make sure she was still there.
Still, as I said, it’s a relatively minor example of characters acting for plot reasons, and it’s not exactly a rare occurence. Chamber of Secrets is one of my favourites of the series, mainly because of the last few chapters (roughly from when they get the note from Hermione about the basilisk). It’s tense, exciting, funny, and thematically rich. All the plot threads are neatly resolved, and you have the classic “hero ventures into cave to slay dragon and rescue fair maiden” trope, nicely undercut because the hero and the maiden are 12 and 11 respectively, and that Ginny – rather than being star-struck and blushing – is upset about being used* and thinks she’s going to be expelled.
And then, we don’t finish with Dumbledore explaining everything, Harry does. Okay, Dumbledore does fill in some gaps, and reassures Harry about what house he should be in (which is a whole other can of worms that I may get into at some point), but it’s predominantly Harry’s show. For now…
* Some distinctly dark implications in this. Nothing blatant, but enough to give you an unpleasant feeling about the whole thing.