A/N: Thank you to everyone who has returned to this story after such a long break, and for the lovely reviews! It's a real boost knowing people are enjoying it.


Severus did not see Lupin after that for several days. He gleaned from a conversation at lunch that the werewolf would be away until Christmas Eve, and felt himself unexpectedly relax. He hadn't realised how much he had felt constrained by Lupin's presence in the castle. Not that he would have behaved very differently in most situations – he would still have avoided the staff room and spent most of his time working downstairs – but somehow he felt freer, less under surveillance, than he had been when his old schoolmate was there too. He spent several evenings in a row playing chess in the staff room with Flitwick, Sprout and McGonagall, with Dumbledore dropping in every now and then to shower them with admiration and cheer. He even began to win some games, mostly against Sprout, who by her own admission was a less advanced player than the other two; but he was making better headway against Flitwick, and even held McGonagall to a draw a couple of times. Her look of teacherly delight at his progress was almost more than he could bear.

He received two letters from Lucius, both short – one promising to arrange a Portkey for Rome and suggesting they rendezvous in London a couple of days before New Year's Eve; and the other somewhat more vivid. I keep imagining stripping you naked and fucking you in front of all the Ministry staff, or everyone at Hogwarts, just to show off my conquest. Severus took this to mean he was forgiven for trying to give Lucius advice.

On Christmas Eve, Lupin was back at dinner, and Severus's mind and body tightened infinitesimally once more, and after dinner Lupin came down to the dungeon for the Wolfsbane. He seemed cheerful enough, but tired, perhaps a little subdued in spirits. 'Dumbledore expressed sympathy that I was missing Christmas,' he said, 'but I can't actually say I'm sorry to be sleeping away the day itself. Yuletide has never been a very joyful time for me.'

Severus gave a grunt and dipped the tongs into the goblet to remove the glowing silvery acorn. He wondered where, or who, Lupin had been visiting.

'Actually,' Lupin said, 'just before I drink it and become – you know – I have a small gift for you. It's very small, I don't want to embarrass you, I just wanted to express some gratitude.'

Severus stared at him, the tongs still in his hand. No one except Dumbledore – and now Lucius – ever got him presents. And Dumbledore's were usually variations on the theme of socks. 'I hope you didn't expect one from me,' he said stiffly.

'Certainly not,' Lupin said, 'since every month you're giving me back my peace of mind.' Then he made a face. 'Sorry, that was cheesy. What I mean is just – thank you, very simply.' He produced a flat parcel, wrapped in dark green paper, and held it out. 'Happy Christmas.'

Severus took it. Clearly it was a book. He hoped to Merlin he wasn't expected to open it right now. The social niceties involved in exchanging presents, the compulsory look of delight when one unwrapped something, were far beyond him. 'Thank you,' he said finally.

Lupin smiled. 'You're very welcome. It won't take you more than a couple of hours to read. If you find it interesting then perhaps we could discuss it after the full moon.'

'You assume I have nothing else pressing to read,' Severus said, thinking of the dozen journals and books stacked in a pile on the floor by his office desk.

'That's true,' Lupin said. He shrugged. 'Well, it's up to you. Shall I drink this now?'

'Fine.' Severus removed the acorn and took it away to dump in the sink while Lupin drank the potion. Then he came back and, as usual, took up his ledger. 'Anything different?'

Already Lupin's eyes had taken on that strange golden quality, that sheen he was becoming used to. 'This all feels normal,' he said. Then he added, rather slyly, 'I hope you're not embarrassed now, knowing how I'm reacting to it.'

'I'm sure I can cope,' Severus said, resisting the urge to roll his eyes.

Then Lupin's face changed. Suddenly he turned away, leaning over the next bench.

'What is it?' Severus said sharply.

'I just – I feel' – Lupin gave a strained laugh – 'ha, I'm just having a somewhat more extreme reaction than normal.'

'Ah.' He realised Lupin had turned to conceal the bulge of a sudden erection. 'The sexual arousal?'

'Yes, I – did you make it differently this time?'

He thought rapidly. 'No, it's the same as last month's. The rosewater will have made a difference but I changed that earlier. Have you ever had it this badly before?'

'Oh, Merlin' – Lupin laughed again and shot Severus a look of – well, he wasn't sure – 'No – it was never like this when I made it myself' – He took a long, shaking breath. 'I think I'd better go upstairs.'

'I'm coming with you,' Severus said immediately. 'I need to understand what this is.'

'No, I'm – I'm embarrassed enough already,' Lupin said, flushing; he straightened up a little, gathered a fold of robe in front of him, and began to walk towards the door. 'I'm sure I'll be fine, I'll see you in a few days.'

Severus strode across and planted himself in Lupin's way. 'There are twelve other people in the castle,' he said coldly. 'If the potion doesn't work, you realise I will need to contain you and make sure everyone can be evacuated.'

Lupin stared at him for a second, then nodded mutely.

'We'll use the Floo,' Severus said. He tried to hold of Lupin's arm, but the werewolf flinched away. 'Best not touch me,' he said, trying to smile. 'I'm not quite sure what I'd do in this state, I'd probably try it on with the Bloody Baron.'

Severus snorted. 'At least you couldn't rip him to shreds. Come on.' He waited for Lupin to join him in the fireplace, then grabbed a handful of Floo powder, shouted, 'Remus Lupin's rooms!' and threw the powder down at their feet.

With a flare of green flames they were there, and Lupin was staggering away from him. 'I need to undress.'

'What?'

'If I transform with clothes on I'll rip them to shreds,' Lupin said, throwing his robes on the bed and beginning to unbutton his shirt. 'I can feel – there isn't time' –

Severus stood there, arms folded, watching Lupin lie back on the bed and yank his trousers off, trying not to look at the visible bulge in his underwear, his fingers tight on his elm wand in his sleeve. His heart was pounding. He knew how to fight a werewolf – in theory – but he sure as Salazar didn't want to put this to the test – and this was all so – Lupin was nearly naked, there was thick hair across his chest and a line of it trailing down to his crotch –

He steeled himself. 'What about now?' he said. 'Anything else abnormal?'

'Not exactly,' Lupin said breathlessly, 'it's all happening faster than usual, so – just – don't look, would you?'

Severus averted his gaze and saw out of the corner of the eye the white flash of Lupin removing his underwear. 'Where do you transform?'

'On the rug,' Lupin said. He hurried over to the fireplace, holding his rolled-up trousers in front of him like a fig-leaf; Severus tried not to look at the outline of his bare legs and buttocks against the firelight. Lupin took a shaky breath. 'Godric and Merlin, this is – I'm sorry' –

'What?'

'Just – I've never transformed in front of anyone before, I've always made them wait outside and lock me in – are you really going to stay in here? It might not be safe.'

'I have to,' Severus said, though he too was wondering about the wisdom of this plan. 'I need to observe you and sound the alarm if you – or you may be in danger, I might have poisoned you for all we know.'

Lupin had summoned a blanket from the sofa and wrapped himself in it, sitting down in front of the fire. 'And if you have? You haven't brought any antidotes.'

'I have a bezoar,' he said. 'That at least would give me enough time to fetch something more specific.' He didn't add that he had kept a bezoar in his pocket ever since the bad days, just in case of – well, just in case.

But Lupin hadn't heard him. His face had gone grey, and he was beginning to shiver, mildly at first, then in violent shudders. The blanket fell away from his shoulders and he collapsed sideways onto the rug, moaning.

Severus moved away to stand by the door, one hand on the handle and his wand in the other – ready to bind Lupin with ropes, to throw fire at him, to conjure a silver knife to stab him through the heart – and to run, if necessary.

Lupin gave another moan, louder and more agonised. Merlin, he was transforming, he was growing fur, his face was lengthening, he was enlarging – his hands and feet were clawed – a tail sprang into being behind his body – he was a wolf.

Severus gripped the door handle, his breathing desperate, ready to fling himself out of the room. God, the size of it. He wouldn't have a hope. Suddenly the wolf raised itself up to its full height by the fire, standing on two legs, huge and broad-shouldered, its eyes golden – Severus took a sharp inhale as it turned its head, but it appeared not to see him – and then its legs subsided under it and it sank onto the floor, unconscious.


He didn't know how long he stood there, watching the wolf. The patch of white cast by the full moon moved a full foot across the floor; the fire was starting to burn low. The wolf breathed steadily, sprawled on the rug, but Severus couldn't quite bring himself to move.

After what must have been nearly an hour, the wolf yawned and stretched out its long, muscular legs, then turned and curled into a neat circle, sleeping for all the world like a perfectly regular (if enormous) dog. Severus forced himself to take a long breath in, and out. All seemed well. He would send a note to the Headmaster and wait here with Lupin for a couple of hours, just to make sure.

He scrawled a message on a spare bit of parchment – Lupin's reaction to potion unusual, am with him in rooms, he is in wolf form, sleeping, seems safe, will stay a while longer to make sure – and, not daring to use the Floo with the wolf so near the fireplace, murmured a charm to send the note flying out of the window and up to Dumbledore's office. Then he lowered himself into Lupin's armchair, and settled himself to wait.