Few alchemical items circulated in the Wizarding World. Aside from those in the Ministry of Magic's Department of Mysteries, more of them circulated among dark wizards.
But most of what dark wizards had were fraudulent trinkets, or alchemical items that cursed and harmed people. Buying a useful alchemical item from that lot could only be described as difficult.
Moreover, alchemical items that protected against curses were extremely precious to dark wizards too. If they learned that Karn was spending large sums to acquire alchemical items, they would certainly try every possible way to make counterfeits and swindle Galleons out of him.
After leaving the potions ingredient shop, Karn visited Borgin and Burkes in Knockturn Alley. When it came to selling alchemical items, Borgin and Burkes did have a little credibility; moreover, its proprietor knew how ruthless Karn was. If he dared deceive him, Karn would raze the entire shop in Knockturn Alley.
"Items that defend against curses, and some wondrous alchemical items? Sir, your requirements are too unusual. I don't know whether I can collect them for you."
The proprietor of Borgin and Burkes spoke cautiously. Although trading with Karn could earn him plenty of Galleons, the man before him was a lunatic who had killed several dark wizards over a disagreement. If he wasn't careful, who knew whether he would be next?
"Then please do your best to collect them, Mr. Burke. If they're genuine, I won't be stingy with Galleons, but if they're fake..."
Karn left the rest unsaid, but the proprietor of Borgin and Burkes knew what he meant. After leaving Knockturn Alley, Karn hadn't managed to buy anything that protected against curses, but he hadn't come away entirely empty-handed either. He had bought some items that could curse other people.
One was a book that could