"Your Highness's interest flatters me, but I'm afraid that I would be ruining myself if I were to surrender th

"Your Highness's interest flatters me, but I'm afraid that I would be ruining myself if I were to surrender the details. It's a trade secret, you see. I can only say that it is my own design, which has allowed me to radically increase the zone of control compared to my competitors' products. While many of the usual charms can capably detect a breach and send out the alarm within one or two buildings, my system is capable of covering several districts... and a whole city if necessary!"