"I have one that I often use to communicate with various eldritch creatures that invade Earth's astral space," Stephen said as he lifted his hands and once more began to draw a concentric circle in the air, "Aptly called 'Unbinding Tongue of Babel.' One moment..."
Correspondence was the Art of relationships, how one thing corresponded to another. Beyond augmenting magicks of sympathy, its chief application dealt in the realm of spaces. One space was connected to another by the distance that laid between them. Which was to say that two spaces could not be isolated from another, because no matter what it was, some kind of shared space laid between Point A and Point B. Mayhap it was a road, or an ocean, or even light years of stellar space. But that space was empirical and thus created a correspondence between the two locations. And that correspondence is what Strange was manipulating.
The circle he drew was an invocation of correspondence and the geometric symbols inside represented the locations from which they originating and to which they wanted to transport. He pushed at the circle's center with a palm, causing it to stretch with a third dimensional depth in front of him.
"The easiest way to move from one point to another is to remove the corresponding space in-between," he mumbled, more thinking out loud than lecturing John in the particulars of his method. The feeling he got from John was that he didn't particularly care.
The trick was, Strange knew from experience, is that you couldn't simply remove the space. You couldn't just delete a river or a road from existence and connect two points without significant consequences. No, it was much cleaner to create a door in space and use that door as the focal point for the practice of Fraying, which was to say fraying the distance. The functional application of such a spell was that when you stepped through the door, you immediately crossed to your desired location because you removed the intermittent space but only in relationship to the door.
Well, portal was the modern term for such a door.
Stephen side-stepped and swung his hand in arc through the stretched circle, effectively cutting through the stretched portion he had created when he pushed it with his palm. The circle warped and widened and spun, the center of it rapidly hollowed until within revealed a city wall.
"Let's go," he said, looking over his shoulder toward Constantine before stepping through the portal.