I have a passage about a character who has just woken up, and then there's the line
The room fell into silence.
Or should it be
The room falls into silence.
I can't get my head around which it should be. Is it a case of tenses? that the former is past tense and the latter is present? the problem is many novels that I read even if the author is describing something which seems to be happening now they still seem to use something like "The room fell into silence"
Can someone point out what the differences are between them?
I guess it's similar to whether I say something like..
I'm sure that's wrong, Harry thinks.
or
I'm sure that's wrong, Harry thought.