"So, Lord Grindelwald –" Sirius started.

"Please, boy, call me Gellert. That 'Lord' stuff means nothing to me anymore."

"Gellert… You didn't know you had a great-grandson?"

"I didn't even know I had a granddaughter." Gellert replied, staring at the floor. "I thought Albus had killed them all."

"Albus?"

"Dumbledore. I assume you know him, or of him. Everyone does."

Sirius remained silent for a moment before he answered. "I thought I did, and now I'm not sure."

Gellert gave the floor a grim smile. "You and me both." He looked at Sirius directly. "What is your name, boy? You remind me of someone I knew when I was much younger."

"Black. Sirius Black, son of Orion Black, grandson of Arcturus Black."

"Black!" Gellert laughed out loud for the first time in decades. "Oh, Merlin's balls, boy. I should have guessed. You are the spitting image of Arcturus' brother Regulus."

"I am?" Sirius had never really heard that before. Everyone always compared him to his grandfather, or to his father.

"Right down to the nose." Gellert shook his head, still smiling. "I miss that boy. He was a wonderful drinking mate. How is he doing?"

"Erm, my great-uncle Regulus?"

"Yes, Reggy."

"Er…" How on Earth did they end up here? "He died a long time ago. I never even met him."

Gellert's face fell. "Did he have any children?"

"No. He never married, never had kids. Died alone." Sirius half-chuckled. "Father did always say I'd end up like him."

"What, a handsome Black lad like you? If I was several decades younger, boy, you'd at least have a companion for the roads ahead, though I'm afraid there's a bit of an obstacle when it comes to heirs in that regard."

Truthfully, this was not the first time Sirius had been hit on by a man. However, he could definitely say it was the first time he had been hit on by a man who was older than his grandfather.

At the look on Sirius' blushing face, Gellert let out another laugh. "I'm just teasing you, boy." He looked back at the paper in his hands. "I need you to tell me more about this."

"I was hoping you could help me fill in the blanks in my own knowledge." Sirius responded, face still a little flushed. "I know the Potter side of things, and I know who Juliet Flitwick is – at least, I think I do. But I didn't even know you had a son."

Gellert smiled sadly, looking at the empty wall, lost in thought. "Ivan. Ivan Gellert Percival. My beloved boy."

"Wasn't Percival the name of Dumbledore's father?"

"Yes. When Ivan was born, Albus and I were not quite yet enemies, though he had been furious that I had married a half-goblin woman. I thought by honouring his father – whom I had respected, despite his mistakes – I could bridge the gap."

"Half-goblin? I thought…"

"That I was a blood supremacist, and that I hated half-breeds?" Gellert pursed his lips. "Most people did. Albus liked to paint me as more of a horrible wizard than I truly was. In reality, Albus was more about Pureblood superiority and a wizard-only magical world than I was. I had no real opinion about blood status, or about magical creatures. If one could do magic, one was worthy of respect. It's the Muggles who were the biggest threat."

He looked Sirius directly in the eyes as he continued. "They're scared of us, boy. Scared of what we can do. Scared of what we cannot do. They use us, abuse us, blame us for things we cannot control. They're the worst kind of being, and they need to be stopped before they wipe us all out. That's what my goal was. Not to wipe out Muggleborns, or Half-Bloods, or half-wizard folk. I didn't care about that. It was the Muggles that were the problem. They probably still are."

"They're not all like that, Gellert." Sirius replied. "I mean, I know a lot who are, but they aren't all so bad. A classmate of mine at Hogwarts had Muggle parents, and they were very welcoming of the wizarding world. They were very supportive, and they loved Isabella as much as any wizard parents would."

Gellert was quiet for a moment. "I have never met supportive Muggle parents. Any Muggleborn I've ever met has had abusive parents, and has had to escape them by going to school or wherever they could get away from them."

"Lily's parents weren't the best." Sirius remarked. "They weren't abusive, but they weren't fantastic."

Gellert looked at the paper. "Lily Juliet? My granddaughter?" He looked back up. "You know her?"

"She was my best friend." Sirius' voice threatened to break. "Besides James, of course."

"James…" Gellert looked at the paper again. "The late Jameson Potter? Charlus' son?" Gellert chuckled. "Good girl, that Lily, marrying a Potter. I can't wait to give her a pat on the back for that."

"She's gone too."

Gellert's eyes went wide, and his head snapped up to look at Sirius. "How?!"

"Voldemort. He killed her. James too. On Halloween."

"Voldemort? That blood supremacist piece of rubbish with not nearly as nice of hair as mine who calls himself a Dark Lord?"

Sirius almost laughed. "That would be him."

Gellert nearly crushed the paper in his fist, before stopping himself, remembering that the paper was still important. "I'll kill the bastard myself."

"You and me both." Sirius parroted Gellert's words from earlier. "He's taken everything from me."

"Just as Albus did to me."

"Dum—Albus nearly took Harry too."

"Where would he have gone? Are any of the Potters still alive?"

"No. Charlus and Dorea were killed by Voldemort when James and I were in our sixth year, and Fleamont and Euphemia died of Dragon Pox not long afterwards."

"What a shame… Fleamont was a good man, and very attractive too. As was Euphemia, and their young son Charlus." Gellert paused for a moment. "Wait, Dorea… That name sounds familiar. Wasn't she of your house?"

"My mother's aunt." Sirius confirmed.

"So then Harry is related to you as well."

"Yes… I have custody of him through not only that, but James and Lily's will." Sirius reached into his cloak and pulled out the will, handing it to Gellert.

Gellert took a moment to read through it, making a few comments along the way. "Longbottom… I knew a Longbottom, she was—Ah, Augusta. Fought with Dumbledore. Very feisty woman, very pretty… Lovegood, I think I knew his father John… Bones, yes, I know that name too…" Gellert let out a laugh. "No custody to Albus under any circumstance, eh? Good for them… Who is this 'Petunia'?"

"Lily's sister, though at this point I'm uncertain they're actually related. She's a Muggle, and was horrid to Lily when they were children because she was jealous that Lily had magic. She married a terrible sort of Muggle who is even worse than her."

Gellert grumbled. "No great-grandson of mine is going to grow up with Muggle filth."

"He won't, ever. Lily and James sought to it. Like I said, I have full custody."

"Good." Gellert continued reading. "Oh, Shacklebolt, I knew his aunt, very nice lady, liked to make tea all the time… Aberforth? He's still around?" Gellert shook his head with a smile. "I'm surprised Albus hasn't arranged an accident for him yet, or hasn't just outright killed him like he killed my son."

"What exactly happened to your son, Gellert?"

Gellert stopped reading the will and looked at Sirius sadly. "Quite a few years ago, around 1971 or so, Albus came here to tell me he'd finally found where my son had been hiding all that time. He bragged that he'd killed him, and his wife, and their unborn child… I guess he purposely didn't tell me that they'd already had an infant daughter."

"Lily."

Gellert nodded. "I can only guess what Albus did from there… Evans is the name of a Squib family member of his. Perhaps he gave her to them to raise, hoping she would never know where she came from."

"What ever became of Juliet, your wife?"

"Ah, Juliet…" Gellert sighed. "I may be what we called 'bisexual' back then, but she always was and always will be the love of my life."

"You used that term back then, too?" Sirius asked. "I thought that was a new thing."

"Oh no, my boy. I learned that term from my Aunt Bathilda. I went visiting her one summer, and that's where I met Albus. I thought he was just the cutest thing ever, and I was confused because I'd already liked girls. I asked her about it, and she told me all about it. She was the only family member I had that was accepting that I ended up having a relationship with Albus."

"Wait… what?" Sirius nearly choked on air. This was far beyond anything he'd ever heard from his grandfather or from Dumbledore himself.

Gellert's eyes narrowed. "I assume Albus doesn't like to disclose that particular information. He became afraid of being associated with me, and he was always afraid of being seen as 'the queer boy'. He hated being public with our relationship, and after one time that Aberforth brought a girl from Hogwarts over and they caught us snogging, he never wanted to do anything."

"I'm so sorry. I had no idea he'd hurt you so badly."

"Does it really surprise you that Albus could be so heartless?"

"I –" Sirius thought about everything that had happened over the last few weeks, and thought back even further to little instances that made him and James start to distrust Dumbledore. "No, it doesn't."

"He's always been that way, my boy. He will never change."

Sirius stayed silent.

"I met Juliet at a bar in London called the Leaky Cauldron. I was there with Aberforth, though Albus had ditched us again, and we met her and her little brother Filius while she was bringing him shopping for his first year of Hogwarts."

"Filius?" Sirius started chuckling. "So Filius Flitwick is really your brother-in-law?"

"You know Filius? He's still alive?"

"He's the Charms professor at Hogwarts."

Gellert smiled. "Good for Filly… Jules always had big dreams for that boy."

"Jules, your wife?"

"Yes. We all called her that. She wasn't a big fan of being called her full name until we got older, but we still called her Jules anyways."

"James hated his full name too."

"Sometimes names are too long, or have bad memories, or just sound too formal. I assume you don't go by Sirius Orion regularly?"

"Of course not."

"Exactly. Names are complicated things."

"So, back to Juliet…" Sirius prompted.

"Yes, of course. I asked if I could buy her a drink, and she said no because she was with her brother, but if I came back the next night I could."

"Did you?"

"Damn right I did. I came back the next night and she was with some of her girl friends, and she seemed surprised that I actually returned. I bought her a drink, and we talked, and… well, we were married a year later."

"And Albus? How did he feel?"

"Like I said before, he was furious. Not only did I 'betray him' by marrying someone else, even though we had broken it off but I was a 'traitor' for marrying a half-goblin. Years later, after trying for so long, he was even more furious when Juliet finally had a son, our Ivan."

"And Ivan married a half-goblin too?"

"Half-goblin women are notoriously attractive, you know. Ever met one?" Gellert smirked.

"No, I can't say that I have." Sirius answered.

"They're beautiful, honestly. The difficulty with half-goblin women is that they often struggle to conceive. I'm sure Ivan and Burga had the same troubles that Juliet and I did, especially since Ivan himself was a quarter goblin, and half-goblin men are usually infertile."

"I had no idea. It's probably a miracle that they nearly had two children."

"Indeed… Does Filius have any children?" Gellert asked suddenly.

"I don't even think he's married."

"What a shame. Filius was such a sweet boy, I'm sure he could have had any witch he wanted."

"He was a very good professor." Sirius offered. "And seemed like a good man."

"If he's anything like he was 35 years ago, then he certainly is."

Sirius stayed silent again.

Gellert looked back at the will. "Who is 'Peter Pettigrew'?"

Sirius' face scrunched up in fury and his hands balled into fists. "He was James and Lily's Secret Keeper since Voldemort was targeting them. None of us had any idea he was on their side, but I suppose James and Lily suspected something based on their will." So

Gellert read the bottom part of the item delegations and started cackling. "Oh, my dear Lily, you picked a wonderful partner, and grew up to be just like your father. This is wonderful, the dung and the sickles."

Sirius grinned. "Yeah, they were always like that."

Gellert handed the will and the lineage parchment back to Sirius. "When can I meet him? My great-grandson?"

"I could bring him up here to meet you whenever you'd like. Or, if you promise not to murder anybody, I can try to get you out under supervision."

"Murder anybody? Why do you think I'm in here?"

"Erm… Murder?"

"Not quite, my boy. You see, Albus and I had this idea… About the 'Greater Good' of the wizarding world. We wanted to control the Muggles, to make wizards and magic-using folk above the ones who couldn't use magic. There were a surprising number of wizards who agreed with us, and it started getting a bit of a following. Ultimately, though, Albus and I got into disputes about who was worthy and who was not… Muggleborns, goblins, centaurs, Half-Bloods, giants, half-breeds… and we broke apart. Those who followed his ideology were louder and more destructive, and they started getting out of his control. He washed his hands of them, and anything they did, he blamed on me. I tried to control them, but I lost my own followers in the process. Eventually it came to me versus Albus."

Gellert's eyes were filling with tears as he continued. "I didn't want to fight him. I just wanted all the death and chaos to end. I wanted the world to go back to what it was. But he loudly and publicly declared that everything had been my fault, my doing, my followers. Since they were all dead, I had nobody to defend me but Juliet."

"Did Albus kill her?"

Gellert shook his head. "I still don't know if it was the supremacists or the Aurors. Either way, he is responsible for it, but he didn't do it himself."

"So you confronted him."

"I did. And we duelled. And I lost, because I was so emotionally compromised that I could barely cast anything but shield charms."

"We were always told that you were in here for inciting violence and for murder."

Gellert shook his head again. "I definitely made some mistakes in my day, my boy. But I never wanted to hurt anybody. I just wanted my people to stop being so afraid to exist."

Sirius made up his mind in that exact moment. "Gellert… I'm going to get you out of here."

A/N: I am in the camp of 'the early early headcanon that Charlus and Dorea Potter were James' parents and were killed by Voldemort/his followers, and that Fleamont and Euphemia were his grandparents is still a fun and valid headcanon' and I will die on this hill.

There's a lot of dialogue in this chapter, but it's a mostly history/storyline chapter, so that's why. Apologies if you hate the way I write dialogue, because I also hate it.

Anyway, I know this goes against a lot of canon about Grindelwald, and there's a lot of points to this story that will stray from canon. But that's the fun of fanfiction, right?

Stay safe and wear your masks!