Realms
"Mary, what's a realm?" Lex finally asked. Currently, he was being carried high in the air by some force, flying quickly away from whatever danger the man had been talking about. It was fortunate that whatever force held him also protected him from the rain and wind. Yet after a while, he was left with nothing to do, and with poor visibility, he wasn't able to see much around him either.
That allowed his mind to wander, and he was finally able to ask some questions.
"The universe is bigger and more complicated than your understanding of it. Your original perception was that the universe, as infinitely vast as it is, is connected by physical space, and that you can traverse that space to reach any destination. That, however, is incorrect.