by darkcloak » Friday 22 April 2005 4:09:47pm
I think there would have been too many variables. If they went back in time and changed just the slightest thing, then there could have been even more serious implications.
Perhaps Hermione or Ron would have been killed, perhaps Sirius would have died anyway or Harry might have been captured in some other way.
I see it like this: They were fortunate the first time they used it, it would have been dangerous to try again.
Anyway, if you really think about it, if they could have used the time turner to save Sirius, we would have 'seen' them do it at the same time i.e. like the BuckBeak story, and Sirius wouldn't have died at all. Therefore they never used it.