'Remind me again why we're doing this?'

Newt pushed himself up from the ground with a groan. It was fifth time now. Across the dimly-lit room, Queenie grinned and lowered her wand.

'Because we're at war,' Theseus said impatiently. 'And we all need to know how to fight. Stop complaining, Newt. Look at Leta - she's doing just fine.' Theseus seemed to grow taller as he admired his fiancee with pride.

Newt glanced to his left, where Leta was holding her own against Tina. Sparks flew between the two witches as they duelled.

'That's not fair,' Newt complained with a pout. 'Leta practically is an Auror. Besides, her partner's not a Legilimens.'

Queenie looked a little hurt. 'I don't mean to do it, honey. It's just you think so loudly when you're duelling.'

Theseus sighed loudly. 'That's my point, Newt. Stop thinking so much. Trust your instincts, Newt.'

'Fine,' Newt grumbled as he got to his feet and went to retrieve his wand. While he was at it, Theseus gave Queenie a few pointers, which she absorbed gratefully. Unlike Newt, Queenie was learning very quickly under Theseus' tutelage, not least because she could hear every little piece of criticism that floated through his mind as he assessed the pair of them.

'Again,' Theseus called. 'And...go!'

'Expelliarmus'

'Protego'

The Shield Charm erupted from Newt's wand with the force of an Erumpent in heat. Queenie's spell rebounded so quickly that she barely had time to dodge out of the way.

'Good, Newt, much better!' Theseus yelled.

More spells darted between them, until inevitably, Queenie deflected Newt's non-verbal Stunner and it spun around and hit him straight in the chest. Newt went flying back and landed with a thud on the other end of the room.

Queenie's hands flew to her mouth as she rushed forward to see whether he was all right. 'I'm sorry, Newt, I didn't mean to!'

Distracted, Tina momentarily glanced over to see what the commotion was. It almost lost her the duel with Leta; she only just had time to deflect a Full Body-Bind.

'I'm fine!' Newt called, rubbing a sore spot on his elbow as he stood up.

Theseus grinned and Queenie smiled with relief.

'Much better,' said Theseus. 'Much, much better. All right, I think it's time for a change.' He raised his wand and sent silver sparks into the air. Immediately, Tina and Leta stopped duelling. They lowered their wands, panting to catch their breath.

'A change of partners, I think,' Theseus announced. 'Tina and Queenie. Newt and Leta.'

This announcement drew a cry of protest from all four parties.

'I can't fight my sister!'

'Leta's going to decimate me!'

'I'm meant to be training too!'

Theseus held up a hand to silence them. 'Look, all that may be true, but in a real battle, you won't get a choice about who you're fighting.' He looked meaningfully at Newt. 'It could easily be someone stronger than you, and you're going to have to find reserves of power somewhere.' Theseus' glance moved to Leta. 'Or it could be someone weaker, but you cannot lower your guard, or they will surely defeat you anyway.' He turned to the Goldstein sisters. 'Or it could be someone you know, someone you love. Many Aurors have joined Grindelwald, including your colleagues at MACUSA. And keep in mind - you may even have to duel Credence, if only to incapacitate him so we can bring him back. You must keep your focus.'

Theseus looked around the group. They were nodded solemnly - the message had gotten across. 'All right then,' he said. 'Let's begin.'

All in all, it went just as they had predicted. Leta was responsible for at least two dozen new bruises for Newt, although he did manage to get in a few sneaky attacks that caught her off-balance. Tina and Queenie had a lot of trouble fighting each other. Tina was terrified of hurting her sister and duelled so defensively that Queenie barely glimpsed a curse or hex. Queenie, on the other hand, figured she might as well use this opportunity to practice her attacks, seeing as she was never going to get past Tina's defences anyway, but she stuck to the most benign spells that she knew.

'Okay, enough,' Theseus finally called. 'Switch again. Queenie, you take a break. Newt and Tina. Leta and me.'

Queenie seemed to be the only one pleased with this scenario. She could tell what Theseus had in mind, and she was glad to be out of it, at least for now. The other three was less pleased.

Theseus raised a hand to stem the protests. 'Look, we all hope it will never come to this. But the Imperius curse is a reality. Just imagine - if each of you were placed under the Imperius curse and told to kill your partner, wouldn't you want your partner to fight back as much as possible?' Theseus paused to let this sink in.

The air in the room suddenly seemed very heavy. It settled in their hearts like mustard gas, and they had to fight to stay focussed.

'We understand, Theseus,' Leta said softly, her eyes dark. She was evidently praying that Theseus would stay true to his own advice and be prepared to defeat her if she was ever turned against him. Yet somehow, she doubted he would, and this doubt flowed through her limbs and made her feel numb and helpless.

'All right then,' said Theseus. 'We're going to do this differently. No Disarming or Tickling or any sort of nonsense. Stunners only, as strong as you can manage. Fight like you mean it. Queenie, you keep watch. Let's go.'

And so they began. The truth of Theseus' wisdom flooded through their veins and they fought like they'd never fought before.

Newt and Tina were battling it out, jets of light flying between them, dodged or deflected with hasty Shield Charms. Tina was clinical, powerful - nothing got past her. Newt was haphazard, unexpected and full of surprises. They were evenly matched at the start, but Tina soon saw an opening. With tears in her eyes, she flung the sharpest Stunning Spell she could. Newt fly backwards, soaring high into the air. The flight was so dramatic that it looked as though he could break several bones upon landing.

But his landing was soft. Queenie, thinking way ahead, had conjured a Cushioning charm and was already waiting when Newt landed by the far wall, slowing down gently as if attached to a parachute.

'Rennervate,' said Queenie, her wand at Newt's chest. Newt's eyes flickered open. He caught a glimpse of Queenie's friendly smile before Tina dashed over and gently pushed his hair back from his eyes, her own eyes brimming with tears.

'It's all right, Tina,' said Newt. 'I'm fine.'

Meanwhile, across the room, Leta had finally broken through Theseus' defences and sent him flying into the air. Queenie reacted immediately, cushioning his fall and rushing over to awaken him.

But Leta got there first, and was cradling Theseus' head in her lap as she pointed her wand at his chest.

'Well done, love,' Theseus murmured.

But Leta was furious. 'You let me get through!' She stood up and walked a few paces away. Theseus sat up slowly, rubbing his head and wearing an expression of dignified confusion. 'Darling, what do you-?'

'You could have blocked it!' Leta was shouting. 'You could have, but you didn't. Because you, Theseus Scamander, are a coward.' Tears were glistening in her brown eyes. She shoved his wand back into his hand, then stood back, raising her arms to her sides. She tossed her own wand onto the ground. 'Stun me.'

'Leta, darling -'

'Do it! You said so yourself. What if they put me under Imperius? You'll have to attack me. Do it, Theseus. DO IT!'

Theseus raised his wand and looked Leta in the eye. His hand shaking, his heart pounding, he gathered his wits and yelled. 'Stupefy!'

Theseus wasn't Head Auror for nothing. His Stunner sent Leta flying backwards and crashing into the back wall, sliding to the ground with a thud, completely unconscious. Theseus was half-sobbing as he ran over to her. Unable to speak properly, he waved for Queenie to revive Leta with a gentle 'Rennervate'. When Leta came to, her eyes were so full of pride and relief that Theseus could do nothing more than hold her close and sob into her shoulder, while she, still weak from the impact of the Stunning Spell, clung to the back of his shirt.

Newt had been watching the entire exchange from his perch of the stone floor, wide-eyed and flabbergasted. He was just wondering if he could do such a thing if Tina asked it of him, when his nightmare came true.

'Newt,' Tina's voice was quiet but stern. No room for argument there. 'You too.'

Mirroring Leta's actions, she pressed his wand into his hand and tossed her own to Queenie, who caught it with surprising grace. 'Go on.' Tina backed away a few paces and spread out her arms.

Newt raised his wand and, fearing he might never perform the spell if he hesitated, rushed into the spell. 'Stupefy'.

The spell hit Tina at an angle, sending her spinning furiously through the air. Unlike with Leta, Queenie reacted quickly and caught her sister with another of her Cushioning Charms.

'There, that wasn't too hard, was it,' Tina said when she woke up. Her attempt at frivolity drew the tiniest smile from Newt, which she took to be a success.

'Now, one more switch,' said Theseus. He had mostly recovered from his ordeal, though his left arm was still firmly wrapped around Leta's shoulders. 'Tina and Queenie. Newt and myself. Let's go.'