I don't mean any methods. I don't care if it's a time machine or magic. That's not my question. If a guys goes back in time, how does he not materialize inside solid rock or a tree, or some building. Here's another scenario. Let's say there are two guys, good guy, bad guy. They both know about a certain method of time travel. The bad guy goes through first and for some reason the good guy has to wait. The good guy goes outside and his entire world is different, maybe some dystopia. How could the good guy even exist? How would his lineage have been present? How could he even have been in the same place. As soon as the bad guy went back in time and changed everything (assuming traditional linear timelines), wouldn't the good guy just cease to exist? I ask this because I was writing a story about it so the good guy can chase the bad guy through time. But if they don't go through at the exact same time then it seems the whole idea breaks down. It isn't like hard sci-fi, it's more of a magical kind of reason for the time travel, so there's no science. The sci-fi part is time travel...or is that fantasy I hope this made sense. Thanks for any comments.