Although Tver had agreed to guide the D.A. students that evening, he was still a professor after all, and professors never lacked classes to teach...
So it was only after he had eaten dinner in his office and finished grading the students' papers that he strolled unhurriedly toward the Room of Requirement.
It was still the familiar eighth floor, but this time Tver's destination was not the headmaster's office, but a solid stretch of wall.
"A place to practice."
With practiced ease, he opened the door to the Room of Requirement and stepped inside, only to find.
A vast crowd of students.
"Professor Fawley!"
A young wizard standing near the door, absentmindedly twirling his wand, spotted Tver at once.
That shout immediately drew the attention of every student in the room. After all, they had come precisely because of the professor.
"Make way. I'm Harry Potter! Let me through so I can talk to the professor about tonight's session!"
With Ron and Hermione helping him, Harry struggled to shove his way through the excited students pressing toward the entrance.
And naturally, his destination was the professor.
"Prof. Professor..."
Harry had only just caught his breath when Tver beat him to it.
"I don't remember the D.A. having this many members. Why are there so many people here tonight?!"
Hearing the blame in the professor's voice, all three of them instinctively shrank back a little, but Ron, who had untied the knot in his heart that morning, forced himself to step forward.
"Because... um... alright, actually, word that you were coming to guide everyone got out by accident..."
Ron explained while avoiding Tver's gaze. He certainly did not think that just because the professor had kindly talked things through with him that morning, he would let this mistake slide.
"By accident? Looks to me more like you were showing off on purpose."
Under Tver's death glare, the three of them lowered their heads fearfully and mumbled a few weak excuses, but clearly did not dare keep "explaining" themselves to him.
Seeing that, Tver irritably rapped each of them on the head.
"Umbridge banned the D.A. through a Ministry Educational Decree. If she finds out you're gathering here, then even Dumbledore and I won't be able to stop her from punishing you!"
Tver had never specifically told Harry and the others to keep it secret, but D.A. meetings were forbidden in the first place, so he had assumed they would never be foolish enough to spread the word themselves.
But now there was such a huge crowd packed in here that forget someone informing on them, if Umbridge simply paid a bit more attention to what the students were talking about, she would discover this place easily.
"Professor, we don't actually need to worry about that for the moment." Draco somehow appeared beside them and spoke with complete confidence.
"Umbridge left Hogwarts early this morning, and up until I came here, I hadn't seen her come back."
Tver looked at him oddly, and both Harry and the others voiced the same question.
"How are you here?"
"Obviously because of you, Professor," Draco said as if it were the most natural thing in the world. "I heard you were coming to teach them the Patronus Charm, so I asked... someone else to bring me."
Neville, who was standing behind Draco and eavesdropping on their conversation, immediately gave Harry and the others an awkward smile.
After all, Draco was a Slytherin. Neville, a Gryffindor, being friends with him was one thing, but bringing him along to a student gathering that excluded Slytherins was another. The fact that Draco had not already been thrown out was only because he had tried to keep such a low profile.
"I think you just wanted an excuse to show off your Patronus," Tver said helplessly, then turned back to Harry and the others.
"Because of your recklessness, Umbridge will find out about this place, and how to get in, sooner or later."
"So either you suspend your meetings, or you move them somewhere safer."
He swept his gaze over the surrounding students, especially those who had already been part of the D.A. for some time, and they all looked back at him pitifully.
"Since Umbridge got an early holiday, we'll let it go tonight."
"Woohoo!"
The young witches and wizards immediately burst into excited cheers, and the room grew noisy again.
"Alright, let's make use of the time we have." Tver waved a hand, restoring order the way he would in class.
He looked around and realized that this gathering actually included students from first year all the way up to seventh year.
Even if every lower-year student had Harry's talent, there was still no way they could learn the Patronus Charm in a single evening.
He let out a helpless sigh and raised his voice.
"Given how uneven your skill levels are, I need you to group yourselves by how well you can cast the Patronus Charm, not by year-"
"Professor," Hermione reminded him in a low voice, "we already tested them in advance. From the students on the outside to the ones farther in, their mastery of the Patronus Charm improves step by step."
Tver looked toward the far end of the room. There really were fewer people there, and he immediately nodded in approval.
With Hermione around, even their recklessness was intelligent recklessness.
Looking at it that way, the number of students gathered here tonight was not actually as overwhelming as it had first appeared from the outside.
He made a quick estimate and realized it was about the same as teaching one full year across all four Houses, which immediately made him feel much more at ease.
"In that case..."
Tver strode toward the center of the room. The students there were of middling skill, mostly people who had attended a few D.A. meetings or studied the Patronus Charm on their own, and could already produce a little white mist.
They were also the students most likely to gain a basic grasp of the Patronus Charm in a single night.
"I'll explain some things first, and then you'll practice on your own. But be aware, I won't be able to give every single person detailed guidance. You'll need to ask other students for help, especially those who've already mastered the Patronus Charm."
He pointed at the Weasley twins, who had been happily watching the spectacle unfold, and startled them both.
This time it was the other students who started laughing.
Still, many of them felt a little helpless.
They really did want the professor's personal guidance, but there were simply too many people here, and the Patronus Charm was not some advanced spell that could be learned just by reading a textbook. It was impossible for him to coach them one by one.
Once they had all accepted that, Tver chose his moment and gave his wand a light wave. A strand of pure white mist drifted from the tip.
"So first, we need to be clear on one thing. The Patronus Charm exists to fight Dementors."
"It's only because our hearts can't be as single-minded as a Dementor's that we need a Patronus to gather and shape the good power inside us."
"The purpose of your Patronus practice is simple. To deal with Dementors."
"So..." Tver spread into a grin.
"I've specially prepared a whole group of Dementors for you!"