"That's right, Gillyweed." Professor Slughorn nodded with a beaming smile. "It isn't a magical item; it grows naturally. I imagine any tests and such shouldn't detect it."
"That really is a good option." Moody nodded repeatedly. "Gillyweed would ensure he could breathe underwater, and if I remember correctly, it also makes you grow webbing. That takes care of underwater mobility too. But can the stuff last an hour?"
That last question was naturally directed at Professor Slughorn.
"Well..." Professor Slughorn hesitated too. "It's affected by the body of water, and there are differences between varieties from different regions..."
As he spoke, he turned to Professor Sprout beside him.
Although Professor Slughorn used Gillyweed in his potions, he did not use much of it. Besides, compared with the effects of the ingredients themselves, he knew more about the new effects produced by combining different ingredients.
When it came to the magical plants themselves, Professor Sprout, as the Herbology professor, was naturally more of an expert.
"Horace is right." Professor Sprout nodded. "In theory, taking Gillyweed could indeed handle the conditions we currently know about. But as Horace said, this herb's effects aren't very consistent. It isn't just a matter of variety and place of origin; the person's constitution matters too."
"Could we try it out? We still have quite a bit of time," Professor Lupin asked.
"We could..." Professor Sprout hesitated. "But Gillyweed isn't a commonly used herb, and it isn't cheap."
"Professor, money isn't a problem," Harry interjected.
Professor Sprout paused slightly, then a smile spread across her plump face. "I'd forgotten that Potter is quite wealthy now. That makes things easy. I know a herbologist in Spain who grows it. Getting some here won't be a problem."
"Yes, we can settle on that as one option. But I think