Secret magic? That makes even less sense to Sam than the name. Not that Gandalf's magic had often been as...as visible as the magic here, but it had never been secret. Everyone had always known he was a wizard, whether they liked the idea or not.

But he smiles at Hermione, hoping to look reassuring. "I won't tell a soul nothing you don't want," he promises. "But I'd dearly love to hear more sometime, if you're willing. Thank you, Miss Hermione - and thank you for the water, and the magic!"