Philip can explain... with a bit of effort. "Okay... So time/space is a continuum. Imagine that..." He draws a little circle on the sand. "That is 'space', the physical occupation of mass inside the universe. And these..."

He draws some lines radiating off it. "These are time lines. This is very, very simplistic, but run with it." He draws a square in between some lines, not touching any. "This is Duplicity, if we're right and it's a pocket dimension. It has nothing to do with any timeline, time runs at its own place. So you can be taken from here." He points at a place on the line. "Into the square. And back again. Make sense?"