"Hi. We're interested in the Patronus Charm. Is that something you'd be willing to help us with?"

The Professor blinks and clicks her tongue. "That is a very difficult Charm, one that even, what is the name, N.E.W.T. students are not regularly taught."

"It didn't sound especially difficult in the book. What's so hard about it?"

"Unlike most other Charms, it requires a very specific frame of mind to be attained and maintained, othervise it vinks out. There are also aspects relating to personality and self-confidence that are not yet vell understood."

"...I'd like to try it anyway. Is it safe to practice on our own out of the book?"

"...vell, unless you are a Dark Vix," and she shoots Sadde a meaningful glance, "it should be fine. But you are very unlikely to succeed even vithout a Dementor around, and they make casting the Patronus much more difficult."

"Does something weird happen if dark wixen try to cast Patronuses?"

"Not all people who could be called Dark Vixen suffer this fate, but trying to cast the Patronus Charm has been known to instead produce maggots that eat the vix."

Sadde blinks and shudders. "That's horrifying."

"Well, neither of us are Dark," says Miranda. "But thanks for the warning."

"You are quite velcome. Vas there anything else?"

"Can you cast one, as long as we're here, so we can see it?"

She nods. "Indeed not. However, these cannot be faked and are proof against the Dark Arts, and vill find their intended targets no matter vhere they are, instantaneously."

"Instantaneously?"

"Vell, if the target is far enough avay, they disappear from where they were cast and appear near the target."

"Wow!"

Sadde nods.

The Professor dispels her Patronus.

"Thank you, Professor."

"You are velcome."

And off they go. "That was neat," opines Miranda.

"Yeah. When we learn to do it I'm partially retiring Richard."