"The universe follows a five-thousand-year cycle. Once during each cycle, all the worlds line up."
The agitated middle-aged man gestured at a blackboard covered in mathematical formulas, then looked around for something he could use as an analogy.
"Here we go. Imagine this is our world."
The man produced two mismatched shoes from somewhere, holding one in each hand. He raised them as he explained to his audience:
"Look! This one is another world."
"Normally, they're separate..."
The man paused, apparently studying his audience's expressions.
Suddenly!
"But! When the worlds converge, everything becomes connected."
The man aligned the opening of the shoe in his left hand with the one in his right, pressing them tightly together.
"Like this. All the Nine Realms are passing through one another."
As he walked, the man showed everyone the shoes in his hands. He lifted one, then pushed it hard against the other.
"Gravity, light, even matter will be squeezed from one world into another!"
Under his manipulation, the shoes abruptly separated, then pressed tightly together again a second later. Leather struck leather with dull smacking sounds.
The man's gaze grew unfocused. His grip on the shoes tightened, and worry lingered in his eyes.
"...If all this happens now, the consequences will be catastrophic!"
But a moment later, his expression changed completely. The corners of his mouth rose in a faintly smug smile.
"However, my Gravity Measuring Device can stabilize the situation. That's right! It can stabilize the convergence points!"
He set the shoes on the table and picked up two pencils from the bottom of the blackboard.
With considerable pride, the man slowly inserted the pencils into the shoes, then lifted the shoes again to show everyone.
"Just like this, the other worlds and their alignments will slide right past us. Ah, how