They were powerful because they'd once belonged to Nicolas Flamel, the famous alchemist and former working partner of Albus Dumbledore. Harry had acquired them in a game of poker, played in a seedy, backstreet Paris revue bar. Harry hadn't exactly played fair. But he'd hunted all over Europe for this set of items, and he wasn't about to let some gnarled old Norwegian warlock hold onto some of the most powerful magical relics in the world just for the sake of his conscience, now was he?