He spent the whole of St Stephen's Day alternately testing the Firebolt and practising Occlumency. It was difficult work. Testing for curses was exhausting, and potentially very dangerous, and he needed to keep himself sharp. And there were the memories, things he didn't usually have trouble keeping at bay, random, disconnected images that invaded his mind every time he detached the copper testing rod from the broomstick and let his protective wards drop. The sheet of calculations he'd made about coconut milk. Pyotr, laughing with his friends in the pub, with his eyes locked on Severus's across the room. The mushroom Severus had made to grow before his eyes, aged eight. A dark-haired Slytherin girl just out of school whom he had helped to recruit for Voldemort. His own reflection wearing the black silk dress robes and looking astonished. Lupin's face, lengthening and growing fur. The piles of books he'd unpacked into his new flat after Pyotr's death. Lucius sitting with the dark-haired Slytherin girl on his knee as they watched some Death Eater entertainment. His own tired mother, taking her wand out of a drawer every morning after his father had left for work. And finally one he'd not thought about for a very long time: the moment in Ollivander's when he'd first held his wand – elm, ten inches, very straight – and felt the lifting of a new realm in his mind, this whole kingdom of possibility.

The images were potent, and persistent. After each session of testing it took nearly an hour of sitting, breathing, clearing his mind, to bring himself back to a firm reality. By eight o'clock he was utterly drained, having tested for everything he could think of. He decided to stop. Short of getting on the broom himself and taking an experimental flight in the dark – out of the question, anyway, with all the Dementors – there was nothing more he could try. He would leave the rest to Flitwick, who had an exceptionally sensitive touch for these things, and to Hooch, whom he'd seen communicating with brooms as if they were actually alive; no doubt she would have a vastly wider investigative repertoire.

He was too tired now to do much else. He remembered Lucius's comment – I thought all teachers spent their holidays lounging around, recovering from the holidays – and his own retort: Only people who've never taught think that. Well, quite. He'd barely had a single day off since term had ended a week before. He might have known that Lupin and Black would contrive, between them, to smother his life with extra worries and duties and hindrances. Anyway, he would go to bed now, sleep it off, and wake early so he could spend the whole morning reading Gondolini's book. He wanted to finish it by the time Lupin returned from his wolf-state, he wanted time to digest it, to think of things to say about it.

He went up to the staff room to find McGonagall, who was sitting bolt upright in an armchair, reading the latest issue of Transfiguration Today. 'I've finished,' he told her. 'Nothing I could find.'

She looked intently at him. 'You're sure?'

'As much as I can be. There is a lot of magical presence, but none of it is Dark magic – and it's closely woven, it feels like it's all been done in one batch, by one person, so I would guess these are just the manufacturers' spells. But of course this is not my area.'

McGonagall nodded. 'Thank you.' She smiled. 'You deserve a good holiday now.'

'What I deserve,' he said as he headed towards the door, 'is for Potter to be disqualified permanently from the Gryffindor Quidditch team for being a profound inconvenience.'

He left McGonagall spluttering in protest.


The next day he spent a pleasurable morning finishing Gondolini's book and writing notes. He certainly wanted to discuss the book with Lupin. But he needed to get his thoughts in order. Magical theory was not something he'd worked on much for years, and Gondolini's writing style was dense, full of analogy and metaphor; in places it was difficult to tell exactly what she actually meant. A large proportion of the book was spent theorising about exactly what a person's magical cadence was, and how to become intimate with it. Severus could follow most of it, but only just.

Her closing remarks, at least, were fairly clear. We behave, she wrote, as if magic is something always external to us, a fruit we have to keep picking, a glass of water from which we must always drink. We stuff wands with potent magical materials and sell them to children who have already been doing magic without wands for years. We teach them always to use the same words for their spells, the same words we were taught. We design potions with twelve, sixteen, even twenty ingredients, as if our bodies were steel cages the potion must break into to have any effect. So rarely do we go into ourselves and see what magic is already there, how we might work with it, how we might let it lead us …

What she was proposing amounted, as far as he could see, to a total overhaul of most European magical disciplines. Potions as he taught it would be annihilated – as would Transfiguration, Charms, and possibly Defence – in favour of a system much more rigorous and complex, in which each person built their own magical repertoire from scratch. It had enormous potential: wandless magic, potions with only a few ingredients, young witches and wizards writing their own spells from an early age. There was also a section about magical creatures, particularly those closest to humans, such as vampires, werewolves, and Veela. Severus wondered what Lupin thought of Gondolini's suggestion that lycanthropy might be curable if scholars paid more attention to how a person's magical cadence changed when they were bitten. He wasn't sure how plausible this really was, but he was no specialist. Still, even if this proved impossible, at least her ideas could one day mean a much quicker, and cheaper, version of the Wolfsbane.

He took lunch in his rooms, partly so he could keep making notes, partly so he didn't have to witness Potter's impatient, ungrateful agitation about his broom. Then he went out for a long walk, climbing up the ridge which ran from hill to hill behind the castle, and walking for hours amid the changing views, the land folding and twisting into the distance. He stood for several minutes in the strong wind which swept through a cleft in the ridge, wondering: did the wind have its own magical cadence? Did the rocks?

After dinner, he played three games of chess with Flitwick, and drew them all. 'You're being more cautious than you need,' Flitwick told him, smiling. 'One or two slightly more aggressive moves and you'd have had me.' Severus nodded, knowing it was true now, he was improving. He went to bed tired, and satisfied.


As expected, Lupin was back at breakfast the next morning. Severus met his eyes calmly as he came in, not wanting to appear embarrassed about seeing him transform. But his efforts were wasted: Lupin looked away instantly, a flush clearly visible in his thin face, and took a seat far down the table, immersing himself in conversation with two Ravenclaw fifth-years. Severus watched him nibble a few morsels of toast and take a few sips of coffee and try to laugh at the students' jokes, but there was no doubt he was uncomfortable. Unexpectedly he had one vivid memory of Lupin's naked form, curled in the firelight, about to transform into a wolf; then he banished it firmly from his mind, and addressed himself to his porridge. Clearly he was still a little susceptible from his work on the Firebolt.

After perhaps ten minutes at the table, he saw Lupin get up and hurry across the Hall towards the door. On an impulse, Severus rose and followed him.

He caught up with him halfway up the stairs to Gryffindor Tower. Lupin turned at his footsteps, his flush deepening when he saw who his pursuer was. 'Severus –'

'We need to discuss a few things before I leave,' Severus said.

Lupin sighed. 'I suppose so. Let's go to my office.' Without waiting for an answer he turned and set off; Severus had to walk quickly to keep up.

They went up to the fourth floor, and into Lupin's classroom. The witches and wizards in the pictures on the walls all turned to greet Lupin enthusiastically, gave Severus a polite nod, then returned to casting their extremely successful defensive spells. Lupin placed his hand against the back wall and a door appeared in the wall; he turned the handle and opened it. 'Come in – have a seat.'

Severus took in the room with a glance as he sat down in one of the chairs in front of the desk. It was bright and airy, the windows catching the wintry sunlight. Lupin had kept the decoration fairly minimal, and it was very tidy – not entirely what Severus might have predicted – so the overall impression was a pleasant one, of clean, scrubbed wood and brisk comfort. There were only twenty or so books on the shelves behind the desk: various teaching textbooks, a copy of Gondolini's book, and one or two others Severus didn't recognise. This, he reflected wryly, was what it looked like not to have a serious book-buying addiction – or at least not to have the money to indulge it.

'Right,' Lupin said, sitting down behind his desk. 'Where do you want to start?'

Severus took a moment to gather his thoughts, accustoming himself to being on Lupin's home turf, as it were. 'Are you feeling – normal?'

Lupin smiled. 'Quite normal, thank you. The aftermath all felt very much as it usually does. But you'll have to fill in a few blanks for me, if you wouldn't mind. I don't remember anything much after we took the Floo to my rooms.'

Severus felt a small surge of relief. So Lupin did not remember that he had fallen asleep in his armchair, and wished him a Happy Christmas the next morning. 'You transformed,' Severus said, 'and fell asleep pretty much immediately. I waited for a while to make sure you were unconscious and unharmed. Then I left.'

'Weren't you frightened?'

He raised an eyebrow. 'I wasn't beside myself with joy at the prospect of defending myself against a werewolf, if that's what you mean.'

Lupin nodded seriously. 'Would you have known what to do?'

'More or less. Why do you think your reaction was so unusual?'

'I'm not really sure,' Lupin said. 'Sometimes it's slightly more acute if I've been drinking alcohol, but there were a good few days between, so. Do you have any theories?'

'No theories,' Severus said. 'Only possibilities. I would advise avoiding alcohol for a full week beforehand. And any other particularly stimulating substances or – situations.' This, he assumed, would be enough to convey his meaning.

Lupin laughed. 'You mean I shouldn't talk to anyone interesting or attractive before the full moon?'

'I imagine the threshold is somewhat higher than that,' Severus said coolly. 'But Gilchrist's formula can't be varied according to your state of mind. If your mood changes significantly, so will the effects of the Wolfsbane.'

'At least it doesn't seem to have done any harm,' Lupin said. 'But I'll try to be more careful. Would you like some coffee?'

This startled him. 'I – if you're making some.'

'Yes, happy to.' Lupin sprang up from his chair, and Severus realised the werewolf had cleverly avoided any discussion of exactly why he might have been unusually excited in the run-up to the full moon. Presumably it was something to do with the few days before Christmas, when Lupin had been away. For a wild moment Severus started to piece together a narrative where Lupin had gone to London, owled Lucius to suggest a drink, and the two of them had … – But he managed to steel himself. There was no way to find out where Lupin had been, short of asking him directly, and he was damned if he was going to do that, so there was no point torturing himself. Still, he would put money on Lupin having had some kind of sexual encounter – or at the very least having been in a state of high arousal – during his absence from the school.

'Is it tomorrow you're going away?' Lupin asked from the corner, where he was waving his wand over a coffee pot.

'Indeed.'

'Where are you off to?'

'Elsewhere.'

Lupin laughed. 'Ah yes, that ever-popular holiday destination. So you need me to do the first week or so of the Wolfsbane, that's the plan?'

'Yes. I'll be back no later than the third of January. I can leave you a set of instructions with the changes I've made.'

'Thank you.' Lupin came over and placed a mug of black coffee in front of Severus. 'And you're happy for me to use your equipment and ingredients and things?'

He raised an eyebrow. 'If happy is a Gryffindor way of saying I'll tolerate it, then yes.'

Lupin laughed again, sitting down with his own mug. 'Thanks for the translation. I promise to be very careful with everything.'

'You can certainly pay for any breakages,' he said sourly. He lifted the coffee, inhaled its aroma, then tasted a sip: not wonderful, but not awful. He realised that Lupin hadn't asked him if he wanted milk. Apparently his coffee-drinking preferences had been previously noted.

Anyway, here came the next part of the conversation, and the more difficult. He decided to be direct. 'Has McGonagall told you about Potter's Firebolt?'

Lupin looked at him sharply. 'No, what's happened?'

'He received a Firebolt for Christmas from an anonymous benefactor.'

'What's that, a broom?'

'The most expensive broom available, according to Hooch. Around the five hundred Galleon mark.' Severus paused. 'And it did not arrive by post.'

Lupin was very still, his eyes fixed on Severus. 'What do you mean?'

'It seems it was brought directly into the castle. No one here has claimed responsibility. I assume it wasn't you?'

Lupin's face had been knitted in thought, but he laughed at this. 'You think I have five hundred Galleons to spend on a broomstick?'

'No,' Severus said. 'The general concern, as you might imagine, is that it has been bought by someone with means, and tampered with before being given to Potter. Whoever sent it would have to know that Potter's previous broom was destroyed.'

'Well, that could be anyone,' Lupin pointed out. 'If all the students know, then so could any of their parents by now.'

'Or it could be someone with another source inside the castle,' Severus said calmly. 'A teacher, say.'

Lupin looked at him for a moment. Then he sighed. 'Severus, I'm not a fool, I know what you're trying to imply, you've been worried about it ever since I got here. But I swear to you, I haven't had any contact with Sirius since the day he was arrested. And I hope you don't think I would ever help bring Harry to harm, or anyone else here.'

His face looked open and honest, except for something in the corner of his eyes that Severus couldn't help noticing, a tiny little sideways glance. He didn't think Lupin was lying – no, he didn't really suspect him of being involved in a plot to assassinate Potter. But there was something.

'Well,' he said, 'the hypothesis is certainly that the broom comes from Black. McGonagall has confiscated it and it's undergoing testing.'

'Who by?' Lupin said.

'Me, among others. I spent St Stephen's Day doing it.'

'That's good of you,' Lupin said. 'Did you find anything?'

'No. Flitwick and Hooch have it now.'

'And if it gets the all-clear?'

'I assume Potter will get the thing back.'

Lupin nodded. He looked thoughtful. 'I wonder if …'

'What?'

'Well, what if nothing is wrong with it? How are we to interpret Sirius sending it, if it was indeed him?'

Severus said nothing. He had had the same thought, especially after spending so long testing the broom without finding a single hint of any magic that shouldn't have been there. There was, as far as he was aware, still no clear proof that Black was actually out to kill Potter. What if the Firebolt was a genuine gift from a godfather to his godson? And if so, what – or who – did Black want at Hogwarts?

'Perhaps I should take a look at it too,' Lupin said after a pause. 'I'd be able to recognise Sirius's style, I'm sure.'

'You are familiar with his magical cadence, you mean.' He couldn't quite stop himself dropping the reference, though he knew it would mean the end of his chance to interrogate Lupin.

Lupin leaned forward, smiling. 'Ah, you read the book? What did you think?'

He nodded slowly. 'It's interesting,' he said. 'But very abstract. How exactly she proposes to use magical cadence to design new potions is not at all clear.'

'I know,' Lupin agreed, his hands cupped around his mug of coffee. 'It's the sort of thing I find really exciting to read, but then when I come back down to earth I start wondering about the specifics. I was actually tempted to write to her about her werewolf theory.'

'That the condition might be curable?'

'Exactly. But I decided it might be too risky, I don't know anything about her. Sometimes those who seem keenest to cure werewolves are the ones who hate them the most. And I've learned the hard way, I can't un-tell someone once I've told them. Or rather, I can't stand the idea of Obliviating someone after I've told them something so important.'

This Severus knew only too well. He thought of Pyotr. The moment eight years ago when, lacking words for what he was trying to tell him, he had taken out his wand and levitated the sofa, with Pyotr sitting on it, off the floor. His lover's shout, his trembling, his white face. The minutes, the hours, of silence that had gone by before he had been able to formulate any kind of response.

Now, in the present, he said to Lupin, 'Caution is always advisable. You might impress that on Potter when you next see him. Apparently he unwrapped the broom and handled it even when he knew it was an anonymous gift.'

Lupin sighed. 'I'll talk to him.' Then he smiled. 'I'm surprised you didn't pretend you'd found a horrific, unbreakable curse. Having a Seeker on a Firebolt might make Gryffindor unbeatable.'

'The thought had occurred,' he said dryly, reaching for his cup of coffee and tipping the last dregs into his mouth. 'Any questions about the Wolfsbane, ask them before I leave – I won't be reachable by post for a few days.'

'Glad to hear it,' Lupin said. 'Testing for curses is exhausting, you must be in need of a good break. Happy new year, in advance.'

He nodded, then hesitated, wondering whether to thank Lupin for the coffee. But this was rather more courteous than he was used to being. Instead he stood, smoothing down his black robes, and gave Lupin a final nod. 'See you in January.'


A/N: So, I've finally handed in my PhD, and promised myself I would use some of my free time to get this story going again. I hope to have at least another few chapters for you in the coming weeks. Thank you for your patience, if you're still reading!