A bit of a caution here for some domestic violence. If you want to skip it, I'll summarise the chapter at the end.

Gellert was beginning to suspect that Hermione had been permanently withdrawn from Hogwarts. The coven children had already delayed their return to Durmstrang by several weeks, but the situation was no longer critical and they would be returning that evening. Hermione, however, showed absolutely no sign of leaving for Hogwarts. In fact, his mother seemed to be handing over duties to her like she was going to be remaining at Hexemeer for the foreseeable future.

Of course, she was far beyond anything he suspected they taught at school, and his mother and Lord Gorlois were more than capable of completing her education privately. Of course, considering the situation, it made sense. He felt like he had a lot to learn and he didn't have the ability to teach himself that Hermione had. He needed a teacher, or he'd never study subjects that he didn't enjoy.

So, he was unsurprised when Hermione's elf popped in to summon him up to the office in the lighthouse. What was surprising was that it instructed him to dress for public.

Confused, curious, he pushed open the door half an hour later, climbing up the gloomy spiral staircase to emerge into the brightly lit office. Both witches stood over the massive desk, pouring over a massive runic diagram. Several runic dictionaries and guides were piled on the corners, holding the scroll open and scraps of parchment were tacked over the original runes, bearing modifications.

They both looked up when he entered, and Hermione immediately greeted him with a hug, gliding back around the desk to stand at his mother's shoulder when she was done. He immediately felt suspicious - it wasn't the first time Hermione had hugged him in greeting, but there was something about the fractional pause in that hug that made him think she was about to do something that would cause an argument. It was like she was apologising already, and it made him wary.

'Is Berg coming?' Gellert asked, glancing around the office and finding nothing amiss.

'No.' His mother replied shortly. 'The matter that I wished to address with you today does not concern him.'

'But it concerns Hermione?' Gellert asked. Then, like someone had just performed a freezing charm in his chest, he realised what was going on. 'You've decided to terminate our courting contract.'

At least Hermione's thunderstruck expression disproved that theory.

'You are here because I have decided, and Hermione is in agreement, that you must give up the Elder Wand.'

'I've stopped using it.' Gellert lied quickly. Neither woman understood just how fundamental the wand was in protecting them all, and how badly he needed it if they were to stay safe. He couldn't give it up, not without risking everything. What if the person they were about to give it to lost it?

'You haven't.' Hermione countered sharply. 'I can feel it, influencing you from where you've hidden it in your boots.'

'And what are you going to do? Give it away? Surely you realise how dangerous it could be in the wrong hands?' He demanded, giving up on pretending that he didn't have it.

'It will go to Gregorovitch.' His mother informed him, not a trace of warmth in her voice. 'Who will study it.'

'Gregorovitch?' Gellert spat furiously.

'Yes, Gregorovitch.' Hermione sounded pitying, for some reason. She spread her hands; a gesture of peace that fell on deaf ears. 'He will study it, and see if he can sever it's negative influence. Then you can have it back.'

'He will destroy it.' Gellert argued furiously. The elder wand did not influence him - he knew, he'd felt the way it moulded to his magic. He knew that it was him influencing the wand, and all it did was amplify traits already dormant in his magic. By taking out that trait, they'd be leaving the wand no better than any other.

'Can't you see it's destroying you, Gellert?' The High Priestess gestured with her outstretched hands to his form. 'It's twisting your magic, making you do things you'd never normally do. You were so distracted torturing Frau Fleiss that you didn't even help me defend your mother...'

'I was neutralising her!' Gellert spat back, swiping away a beseeching hand. 'Because I've learned that threats that are not not dealt with quickly and thoroughly come back and get us later.'

'Neutralising?' His mother demanded, looming over Hermione's shoulder. 'She was already neutralised - she had no magic, she was barely conscious. You were so distracted by a twisted need for vengeance that you failed to recognise the real threat.'

'It would have been fine if Hermione hadn't been trying to stop me. If she'd been focused, like she should be.' He levelled a hand at the High Priestess, one accusing finger extended. Her brows lowered, expression turning thunderous to match his mother's.

'I wouldn't have been distracted if I didn't have you succumbing to the evil influence of a cursed wand.' Hermione stepped forwards, jabbing her finger into his chest. 'If you hadn't tried to take a shortcut to power and had worked at learning to duel properly, if you remembered the basic lesson to not trust anything when you can't see where it keeps it's brain!'

'Oh!' Gellert did not back down as his much smaller sister jabbed at him. 'So that's what this is actually about. You're still bitter that I can beat you in a duel? You'd risk the family for your pride?'

'Gellert Grindelwald! You will not speak to your betrothed-' His mother began. Hermione cut her off, rearing up furiously. Her magic crackled dangerously, tangible as her family magic rose up in her defence. Parchment tipped off the desk, quills flew from their pots and the witchlight wavered in the beacon.

'My pride?' Hermione hissed lethally, 'you dare say that this is about my pride? You failed to protect the Matriarch because you were too busy torturing a defenceless woman, who was already beaten. The Gellert I know would never do that.'

'Then perhaps you don't know me as well as you thought.' Gellert sneered. The elder wand had made it into his hand, somehow. He didn't know how, but he was grateful for it. Hermione's family magic swirled uncontrollably with the force of her emotions, snatching threateningly at his own and coils of spectral fire curled from the younger witch's fingers, ready to become real in a heartbeat.

'Oh, I know you.' She spat. 'I know who you were, I know who you are, and I know what you will become...'

'You know nothing!' Gellert roared, shoving her away from him. Bolstered by her magic, Hermione always seemed larger than life. It was easy to forget how much physically smaller she was than Gellert. Caught unprepared for the physical attack, Hermione was thrown backwards, stumbling over the carpet and barely catching herself as she hit the floor. He thought it served her right - she'd been the one to make it physical, with her threatening magic, but he needed to end the argument before it really began, or she could end up truly hurting herself. He levelled his wand at her.

'You have this idea of who I should be, of who you want me to be. I am not that person. And now that my really power is being channelled through the wand, you're afraid.' He accused.

'Gellert!' His mother stepped between the two teens, throwing her arms wide to block his sight of the young witch. 'Can you not see what the wand is doing to you?'

'It isn't doing anything!' He howled furiously, flicking the wand and throwing her flimsy, muggle form aside like a rag doll, then rounding on her when she was on the ground. 'This is me, but you won't let me protect you.'

His mother didn't have magic to instinctively protect her anymore, and the casual toss had left her wheezing and clutching at her leg.

'Do you call this protection?' The High Witch gasped. 'Perpetrating violence against us?'

'You're forcing me to do it.' He shot back. Then his mother's eyes flickered to something behind him and he realised his mistake. He spun, wand raised, just in time to take Hermione's powerful, crimson stunner straight to the chest.

The last thing he saw was her wand, levelled at him. The last thing he felt was the elder wand, tumbling from between his fingers.

Summary: Hermione and Lady Grindelwald ask Gellert to give up the wand to Gregorovitch for study. Under the wand's malevolent influence, Gellert's protests become violent, even as he's convinced that he's somehow protecting them. In the ensuing fight, Gellert raises his wand to both witches and his mother ends up with injuries to her leg. In the end, Hermione stuns him and takes the wand.