"Don't thank me yet." Wait, what's that supposed to mean? A strand of the ward is pulled away between forefinger and thumb and then sharply prodded against Katsuya's chest. It's not painful, but the thread vanishes in a way that's probably disconcerting, slithering inwards and vanishing like some kind of particularly determined snake.

"There. You should get an inkling when someone steps through from your city to the Nexus. Just a sense someplace in your chest, a hunch, if you will. That should be useful either for interlopers or ensuring guests make it back here safe, hm?"

Naugus turns to the door. "Now, just a matter of getting this installed..."