As soon as you go back in time, it would change the future. Since they keep going to the crapping real time to bring people back, obviously nothing has happend and mankind did not survive the 85,000,000 years. <- long time BTW. Or, going back has already changed the future and it's the reason it is so bad in the first place. Story is full of holes,,,,,,,,,, watched 3 times and stopped. As well, they are alreay affecting nature and changing natural paths. Aren't they suppose to be preventing this? As I said, holes, holes, holes!