I still think the second movie breaks one of it's own rules, where Older Biff steals the Delorian, goes back in time to give Young Biff the Almanac, returns to HIS OWN unchanged future, and in the deleted scene, vanishes from existence. How could he return to his own time/reality if he already changed it in the past? Or is the time-change the same as the one in The Journeyman Project (old CDROM game), where the change is a wave that takes "time" to travel from one point in the time stream to another? Where's a Higgs Boson particle when you need one?Remember, all it took was for Marty's dad to start going all Emo on the dance floor in part 1 for him to start vanishing on the stage playing guitar. Yet Biff could go back in time, make a MAJOR change, and still return to his own time?Good movies with weird plot holes bug me.