I shook his hand, then began digging in my pocket for chalk.

"It's a pretty basic process. The important part is the will- the belief. It's like any other spell that way, even if it doesn't require magical talent to use."

I found the small lump in my pocket, then looked back at him, holding it up.

"Step one: Draw a circle. Can be anything, really. You could draw a groove in the sand, or use chalk- it's why I keep this on hand- or whatever. The closer to a perfect circle you get, the stronger the barrier you make."

As I spoke, I looked around for a good spot, but decided that the hallway was too likely to get traffic.

"... Got a surface you wouldn't mind getting chalk on in there?"