How did she know?!
Borgin was startled at first, then frowned slightly.
"My shop deals only in legitimate magical goods. Everything on display has been registered with the Ministry of Magic. There are no other Dark Magic items here."
Hermione nodded.
"In that case, we have nothing more to discuss. Arthur Weasley from the Ministry of Magic is right outside, and he'll be coming in to search the place shortly. If he finds no Dark Magic items, you're welcome to lodge whatever complaints you like. But if he does..."
"I don't need to tell you how much money you'll lose this time, do I?"
Borgin's expression darkened.
Although the Ministry of Magic banned the distribution of Dark Magic items, it was difficult to stamp out their circulation entirely. As long as he wasn't caught and disposed of the goods in time, he would be fine.
But once he was caught red-handed, the penalties were severe.
Enough to cost him an entire year's turnover!
He had certainly heard of Arthur Weasley, too. Lately, Arthur had been in charge of raids on households to seize Dark Magic items. The Malfoy family in particular had received several visits from him.
Now Borgin had no time to dispose of the goods, while Arthur Weasley was practically on his doorstep.
If the items from that last transaction were discovered, not only would Borgin be fined, but Lucius wouldn't get off either. Lucius would certainly come after him, and his shop's reputation would be ruined. Who would dare trade with him after that?
"What do you want?"
Borgin gave her a hostile look.
"Give me everything from that transaction."
Hermione held out a hand.
"This is extortion!"
Borgin flew into a rage.
"What extortion? I'm helping you voluntarily surrender your contraband. It's called confiscating illicit gains.