Minerva was practicing the piano when she heard a knock on the door. She looked at Grindelwald. "Stay there," he ordered, and went to the door that led out into the castle.
Minerva obeyed Grindelwald, as she was wont to do, but that did not stop her from listening carefully to try and discover who was at the door. She heard the Grindelwald and another man speaking and her heart started beating faster. It was him.
She continued playing, hoping that the business would require her father to bring the man up. She desperately wanted to see him again. She smiled to herself when she heard the distinct sounds of the men on the spiraling stairs, and the opening of the door. She turned most of her attention back to the piano so that Grindelwald would not know that she was eavesdropping.
"Sit down, Professor. How may I be of service?"
Albus did not answer for a moment. Someone was playing the piano, and he wondered who it was. The song being played was beautiful, but something about it made him feel a sense of foreboding. It was far too perfect. "I wished to discuss with you what you thought we ought to tell the students about all these deaths that are being reported in the paper. I believe some of them are starting to be worried, and it is of course our job as their educators to make them feel safe." He watched Grindelwald closely.
Grindelwald did not do anything exceptionally suspicious, but he did glance over at the corner where Minerva was playing the piano.
"Who is that playing so exceptionally?"
Grindelwald looked at Albus and then quickly back at Minerva. "Minerva, come here please." He put his hand inside his robes and clutched his wand. He had always been intimidated by Albus. Everyone knew that he was an immensely powerful wizard.
Albus noticed Grindelwald's movement and carefully made ready his own wand. He then turned to see who Minerva was, though he already had a suspicion. He watched as the very girl who had warned him walked resolutely up to Grindelwald and stood beside him.
"Minerva, I would like you to meet Professor Dumbledore. He works in the school. Albus, this is my daughter, Minerva."
Albus bowed slightly with a smile. "I had no idea you had children, Headmaster."
Grindelwald gave a smile that did not reach his eyes. "Just the one. And I hope I can trust you to mention this to no one." It did not matter if Albus promised not to tell anyone. He would not leave the office alive anyway.
"Of course. It's wonderful to meet you, Minerva."
Minerva did not answer. She simply stood, staring into his eyes. He had come.
Grindelwald broke the silence. "Albus, I suggest that we tell the students nothing. It is not our place; undoubtedly their parents would wish to be the ones to explain."
Albus looked at him strangely. "Are you not concerned about this situation?"
Grindelwald answered coldly. "Not to the extent that many are." He saw in Albus's eyes that he knew the truth. It was time to act. Grindelwald sprang up and whipped out his wand. "AVADA KEDAVRA!"
Albus deflected the spell quite easily and began sending back a stream of his own. The sound of crashes filled the office as spells went off their marks and left chairs, pictures, and books as smoldering wreckage. Albus could see that Grindelwald was a very powerful wizard, but fortunately Albus was far more powerful. Before long, Albus had his wand to Grindelwald's chest and the dark wizard was completely at his mercy. "I want you to turn yourself in, Grindelwald. I do not want to kill you, but if you make me I will. If you come cooperatively, you will be put in Azkaban, alive. Minerva will be cared for."
Grindelwald stared into Albus's eyes. "Come here, Minerva." Minerva hesitated. "I said, come here. Now."
Minerva came closer to him. He grabbed her and pulled her in front of him. He pointed his wand at her head, showing Albus what he would do if they were not allowed to escape.
Albus lowered his wand. "Do not hurt her." He looked at Minerva. She was still looking at him, seemingly unaware that her father was threatening to kill her. But perhaps if she had noticed, she would not have been surprised. She had known the truth about him all along. "You will not get away with this. Even if I am not the one to do it, someone will bring you to justice."
Grindelwald hugged Minerva to himself and with a wave of his cloak, they were gone, leaving Albus in shock. He did not even have the power to get around the Apparition guards of the castle. How Grindelwald managed it, he did not know.
Albus immediately went to inform the Minister of Magic and the Deputy Headmaster. "Armando, I think we are in need of a new person to run this school."