After Harry explained that Bill Weasley was not in agreement with his mother and sister, Draco and Hermione agreed to hire him for a consultation; Draco especially needed convincing because, due to a shortfall of funds in Hermione's department, he was bankrolling the cursebreaker's visit.
"I see them," he peered through a magical version of a jeweler's loupe. "Oh, there it goes again." Hermione handed him the plate to which the ball had been batted. "You said you attempted a few spells, with no luck."
She listed them off on her fingers. "We tried finite incantatum, alohomora, and carpe retractum. I considered dissendium but wasn't sure if it would shatter the plate or not."
"Good call on that one. She may have locked it down to her magical signature," he murmured to himself before asking, "Did you get any kind of response from the spells?"
"That's the strange thing. Harry might have been waving around a twig for all the good it was doing."
"As usual," Draco disguised the comment with a cough.
"Oi!" A burst of wind ruffled platinum locks.
"Not the hair, Potter."
Hermione stilled them with a glare. "Yet when Draco and I tried, the plate would glow and quiver before settling back down."
"Really? That blows my first idea out of the water. Do you mind if I try?" At her nod, he began silent casting but, like Harry, received no response. "Now, you two show me," he ordered Hermione and Draco. Sure enough, the effect was repeated. "It's locked, all right, just not too tightly," he muttered. "Let me think..."
While Bill pondered the situation, Harry rifled through Umbridge's file. His hands stilled before he called, "Hey guys. Remember at Hogwarts, Dear Dolores always relied on the backing of the Minister and her lackeys–sorry, Malfoy–but never exhibited much magical power of her own?"
Hermione sniffed. "She wouldn't let us practice in Defence, probably because we'd wax her tail."
Bill and Draco looked confused. "What's that mean?"
"Muggle expression, and beside the point. Go on, Harry."
"Anyway, suppose she tried to lock the spell, but it got locked with her wand signature instead of her magical signature."
"So anyone who used her wand could reverse it," Draco speculated.
Bill cut to the heart of the matter. "What happened to Umbridge's wand?"
Harry waved the folder. "After her conviction it was snapped and destroyed."
Hermione sagged. "So all this was an exercise in futility."
"Maybe not…"
Bill narrowed his eyes. "What are you thinking, Harry?"
The auror turned to his former classmate. "Draco, when I checked your wand around Christmas–"
"You mean when Weasley–uh, Ron Weasley–decided to play with fire?"
"Yeah. It was different from the one I 'borrowed' several years ago."
"As I told Hermione, after the war that one didn't work right, so I had to replace it."
"What are the components?"
Draco sent a questioning glance to the other two, who shrugged. "Birch for the wood, and the core is unicorn hair, same as my first."
"Hermione," Harry focused on her, "you're still using the vinewood and dragon heartstring, aren't you?"
When she nodded, Bill asked, "Where are you going with this, Harry?"
"Umbridge's wand was birch and dragon heartstring."
"The core of mine and the wood of Draco's," Hermione mused. "Bill," she turned to the redhead, "could that be why Draco and I got some sort of response when we tried the spells?"
"Perhaps," he replied slowly. "Are you thinking about trying to cast at the same time?"
"Only if you think it will work."
"Give me a couple days to research and confer with a few folks and I might have an answer better than a guess. But if this works–and that's a big 'if'–what will you do with your freed were-cats?"
"Ailuranthropes," Hermione corrected absently, "and what do you mean? They're still human, just like werewolves, although their transformation is not bound to the lunar cycle."
Draco interjected, "Weasley, are you referring to the fact that these magical beings have been forced into maintaining their animal persona for a far more extended time than usual?"
"Yes, and imprisoned in an extremely confined space."
"Not to mention being bounced around by Umbridge's pets." Harry shuddered. "That's the definition of torture."
"So," Hermione was thinking out loud, "they will be unhappy–no, make that angry–and likely to take it out on us, despite the fact that we will be the ones freeing them."
"They may have even turned feral and be a danger to others, whether they manage to transform back or not."
"Then we will need a heavy duty mind healer as well as a cat whisperer," she mused.
"I'm not sure what a cat whisperer is," Bill said, "but it's a shame that Newt Scamander isn't in England. If anyone could handle the situation it would be him."
Draco spoke up. "I have it on good authority that Scamander has been traveling in the Far East for the past year. However, the love of creatures, even if they are only such part-time, is in the Scamander blood, and it just so happens that his grandson Rolf is conducting an independent research project at one of the more remote Malfoy properties."
The younger Scamander wasted no time in making his way to London and proving that he was a worthy heir of his grandfather. "Most ailuranthropes in this part of the world take the form of a housecat."
"Similar to Headmistress McGonagall's animagus form?" Harry asked.
"Yes, although animagus is a learned procedure and ailuranthropy is a natural and hereditary trait. That being said," he took a deep breath, "there were size and species variations in Europe, and we don't know if any of those crossed the channel before they disappeared over there."
"So we should be prepared for the emergence of traumatized felines from the size of a house cat to a panther," Hermione theorized.
"Don't forget pissed-off humans if they are able to transform back quickly," Draco pointed out.
"And, just like werewolves," Rolf added, "no matter what form these pussy-furs take, they will be stronger than the average person or cat."
"Rolf Scamander," Hermione spoke into the silence following that statement, "I know someone that you definitely have to meet."