"I've tried the Prefects' Bathroom," Draco commented. "It feels decent enough for a bath. There just aren't enough kinds of bubble bath."
"What does that have to do with bubble bath?" Harry reminded him. "We're going there to practice the Patronus Charm, not to take a bath."
"Don't rush me, I haven't finished..." Draco looked at Harry and said unhurriedly, "The bathing experience is one thing. The environment there is another."
"You probably don't understand Vizet's way of using the Patronus Charm as well as I do... The Prefects' Bathroom has luxurious decorations, and the water temperature is always just right..."
"When we're in a place like that, a place made for bathing, can it really stir up our 'survival instinct'? Is it really suitable for practicing the Patronus Charm?"
"That makes sense... The water temperature in the Prefects' Bathroom is restricted. There's no way to adjust it to very low or very high temperatures." Cedric nodded. "I did overlook that."
Harry said nothing. He only shrugged, which counted as accepting Draco's point.
"If you don't mind..." Vizet said, "maybe you can practice right here."
"Practice right here?" the three of them said at the same time, sounding somewhat surprised, yet also eager to see what Vizet would do.
"I can't provide too large a space..." Vizet drew his Wand. "But if it's to simulate the feeling of the bottom of the Black Lake and use that to practice the Patronus Charm, it should be enough."
Ever since he had created the Christmas Ball space last time, his understanding of the Harmonious Space Charm had deepened a little more;
Together with the Harmonizing Herbology theory he had been studying recently, he could refer to the "medium" concept in Ritual Magic and construct a space through more intuitive elements such as