2. Why Didn't They Use The Time Travel Device More? - Harry Potter And The Prisoner of Azkaban
So in the Harry Potter universe, Hermoine has a necklace that is capable of taking multiple people back in time where they can then change the course of past events. Despite having this incredible device, they use it a total of one time in the series. Maybe I'm forgetting some kind of limitation that they talked about or it was explained in the book series, but why on earth would Hermione not use this at all even though Voldemort is about to completely destroy Hogwarts and kill all the wizards later on in the series? Also, if devices like these exist, how is Hermione even able to obtain one? In the movie she gets it from Dumbledore so she can attend more classes, but I find it odd that they would give such a potentially disastrous device to a teenager who pretty much had free reign to do whatever she wanted with it.