"A slave cannot be a master… Magic has judged."
The words reverberated in the great hall of Hogwarts. A number of upper level students at the Slytherin and table and at the Ravenclaw table screamed and died as their bodies were consumed by the slave mark. Minerva McGonagall and the rest of the Hogwarts staff looked on in horror as at their own table Severus Snape, the current headmaster, was reduced to ash as were the two Carrows.
A house elf popped in in front of the staff table. "Miss Minnie, the old old wards are up again."
"The old wards?" McGonagall repeated numbly.
"Yes Miss Minnie, the old wards Master Albie took down so… so…" The elf looked over at the pile of black ash that had been Snape. "So slave people and bad things could get in."
The elf looked around the great hall, at the students who seemed to be in shock at the events around them. The elf stood straighter and subservient puppy dog look the magical humans assumed was the house elves' normal demeanor disappeared to be replaced with something ancient and alien. Sidhe.
"Lady Magic has judged her people and has awoken the old magics. The ones Grindelwald and Dumbledore tried to deny. The ones the Wizengamot tried to tame with laws and wands.
"You need to attend your children," the elf added before popping out.
Flitwick and the other heads of houses started toward their house tables then Flitwick stopped. "We forget that the house elves are among the old races. They obey us because they need us. And Magic help us if they ever decide they don't need us."
Madame Pomfrey turned to McGonagall. "I believe you're acting head mistress. I'll take care of your lions while you notify the Ministry. This event is bigger than just us."
McGonagall hurried to her office to contact the Ministry by floo.
To her surprise Pius Thicknesse, Minister of Magic, answered. "I've been expecting your call, Professor."
McGonagall noted that even in the flame image, Thicknesse looked like a man who had gone through hell. "We've had an incident here," she began to explain, unsure of how to tell him and how much to tell him. She was one of those who suspected Thicknesse had had mind altering magics placed on him by Riddle and his slaves. She also recognized that her own mind seemed oddly clearer. She knew that Voldemort's true name was Tom Marvolo Riddle and his Death Eaters had willingly been marked as slaves by him. She also recognized that her mind had been altered repeatedly by Dumbledore. She knew this.
"All the Death Eaters are dead," Thicknesse said. "Even the ones who may have been forced into it. And all the collaborators in that lie about…" Here he paused and took a deep breath. "Even the word leaves a bad taste in my mouth. All of them have lost their magic. Completely. St. Mungo's is refusing to take them. Apparently even they lost people but one of the healers told me that they can't do anything for them at all. As far as diagnostic spells can tell, every last one of the collaborators is now a muggle."
"How did this happen?"
"We're not sure, but we think one of the accused called on Magic to judge. And she did."
A/N: Dumbledore is NOT a good guy here. He left an untreated injured infant on somebody's front stoop in November. He knew that Sirius was probably innocent of betraying the Potters and hadn't gotten a trial and Dumbledore actively worked to keep Sirius from getting a trial.
These are not a acts of a 'good' man.