The Venn Diagram of Time Travel

Sam: I think Dr. Bright found a way to get Mark back. She called me at midnight last night talking about dimensions and Venn diagrams, water acting as some sort of interdimensional bridge. When you time travel, you're not leaving your circle to go into other circles of time. You need to reach through that point of contact the moment where the lines cross before overlapping and pull him out. For some reason water and bullets apparently permeate the edges of your dimension. They aren't contained by their time circle. Maybe if something moves fast enough, it can break through. Sam: There are things about your power we are never going to understand. But it's the best theory I