Du har rätt i första instans, lyckades Harry inte få tillbaka boken.
Alla är några större och mindre 7: e bokspoiler
And so it burned (as well everything in the room) when Crabbe casted Fiendfyre inside the room in The Deathly Hallows.
Som du kan se här:
"I know what the diadem looks like, and I know where it is,” said Harry, talking fast. “He hid it exactly where I hid my old Potions book, where everyone’s been hiding stuff for centuries. He thought he was the only one to find it. Come on."
och sedan:
There it was, right ahead, the blistered old cupboard in which he had hidden his old Potions book, and on top of it, the pockmarked stone warlock wearing a dusty old wig and what looked like an ancient, discolored tiara.