Severus had been feeling quite cheerful in his first morning back as a human. He was going to the Mook Rehabilitation Centre, and he was free to make that decision for himself. Mr Nutt hadn't specified a particular time to come, so he decided to make some sandwiches, go out for a walk and a swim and then have lunch before turning up to discuss entry.

Unfortunately, going for a walk gave him time to think. Splashing about in the sea (there was probably somewhere on the Rock where he could get gillyweed, if he wanted to explore underwater, but for now he was happy to be a human swimming on the surface of the water) gave him time off from his thoughts. He could focus on the sensations: the cold of the water, the pull of its currents, the crashing of the waves, the feel of sand and stones under his feet when he stood up, and the drag of his waterlogged robe.

It would have been more enjoyable if he had had a pair of swimming trunks, or even underwear that fitted, but for now he needed to keep his robe on for decency's sake, in case anyone was watching and laughing at his pale, scrawny body. He had laid his pointed hat down on the sand. Walking had been surprisingly difficult with an adult-sized hat that kept falling over his eyes, but conical hats had been an essential part of being a wizard ever since Merlin had introduced them – originally as a show of solidarity with Muggle peasants, who at that time wore either hoods or conical hats. If he was expected to choose a new set of clothes, he had to make sure a suitably-sized hat and swimming trunks were on the list.

Jeans, said the memory of his sixteen-year-old self (so, actually older than his current self) in his head. With a belt. So it's not so easy for people to hold you up and show everyone your underpants and then pull them off…

Jeans that fit, added an even younger self – nine, maybe? Not ones mum bought from the Women's Institute jumble sale two years ago. And not mum and dad's cast-offs with the cuffs rolled up. And a sweatshirt with a hood you can hide in if you feel scared.

You'd look good in blue or purple, or something with a floral pattern, said the older Severus he had seen in the mirror, in a dream. It's cool looking like a vampire or a wicked witch in a Muggle fairy-tale, but you don't have to be a Goth every day. Of course, neutrals work, too, he added, and flashed on Severus's mind a mental image of older-Severus at a historical re-enactment day where everyone else had come as a Roman so he had decided to come as a Briton in a dull beige tunic, beating off the Roman invaders with a shillelagh. If Severus had turned up for an event in a different costume from everyone else, he would have felt humiliated and covered it by sneering at the others, but older-Severus was clearly doing something different just for the fun of it, laughing happily without a trace of malice.

Where did these people come from? Was he going insane, his mind separating into parts, the way Mark Vorkosigan's had? Then why would it happen now, rather than when his life had been at its most painful?

No, said nine-year-old Severus. We're not cut off. We're just parts of you. We're the memories of who you have been.

And who you could be, added older-Severus. You don't know what all the options are, yet.

'I know what happens to me when I start thinking there's hope!' Severus snapped, aloud. He felt furious again – with Mr Nutt, with Cheiron, with all these alternative versions of himself. The last time he had felt full of hope was just before going to Hogwarts, when he had been convinced that everything would be different once he was away from Spinner's End and his parents, and that he and Lily would make friends with more people who were different like them, and have a wonderful time. For years his Patronus had centred on the memory of not happiness, but of having once believed that he could be happy.

But he had a new Patronus now, didn't he? He put on his hat, picked up the pearwood wand from underneath it, and called urgently. 'Expecto Patronum! Expecto Patronum!'

There was nothing. On the third attempt, he managed a thin wisp of silver, which gave a sad little miaow before fading.

Well, he'd never seen a Dementor on the Rock, so he didn't need a Patronus to protect him, so he didn't need happy thoughts, did he? He'd managed without happiness up until now, after all. Cheerful, relaxed older-Severus was a dream, nothing more. The whole point of the Mirror of Erised was that it was a snare, reminding you of all the things you longed for and could never have. He had thought it was showing him that he wished he could have lived long enough to find love, get married and have children and grandchildren. But maybe what it had really been taunting him with was the hope that, if these things had happened, he could have been happy, and that his children would have loved him, instead of hating him and wishing they had never been born. He remembered, now, a detail that he had barely noticed in the dream when he was dreaming it: a portrait of him in the deliberately unrealistic colours of purple, magenta, turquoise, lime green, sky blue and yellow, painted by one of his sons and proudly inscribed in Gothic script with the words 'Nasty Professor Snape is my dad.'

He couldn't be bothered to go to the Mook Rehabilitation Centre. Cheiron and Konstantine were right; it would be just one more place where he didn't fit in. He picked up a pebble to try skimming it on the waves. It crashed into the sea with a splash. Of course, he could have made the stone bounce by magic, but what would be the point? He collected a few more pebbles, and instead of skipping them, used his wand to make them shatter or explode just before, or just after, they hit the water. The pearwood wand wagged its tip eagerly. It enjoyed destructive magic nearly as much as it enjoyed casting protective spells, and Severus was playing this game as much for its amusement as to relieve his own feelings. He felt angry enough that he could easily have exploded the pebbles without needing the wand as a focus.

He was so engrossed in the game that he didn't notice when a small figure appeared on the beach next to him. 'Good afternoon, Severus,' said Mr Nutt. 'Your Patronus came to fetch me.'

'I can't make a proper Patronus any more.'

'Is the small silver cat not yours? It insisted that I come to find you.'

'No, it didn't. I've never been able to make a talking Patronus.'

'Well, its precise words were "Miaow."'

Mr Nutt was trying to look as unthreatening as possible. He was about the size and build of an adolescent goblin.

'You don't need to patronise me,' growled Severus. 'I already know you're an orc.'

'And I know that you are a thirty-eight-year-old wizard. Is that any reason why you should not appear as a teenager, or as a cat, when you wish?'

Severus didn't reply or look at him, but found more stones to explode – making sure that he threw them far enough out to see that they didn't hurt the orc.

'If I ask, "How do you feel," will you want to answer?' asked Mr Nutt. 'Either here or somewhere more private?'

Severus cast a silencing charm around them, to prevent eavesdroppers. 'I suppose you want to know why I'm not at the Mook Rehabilitation Centre to sign up for classes and therapy?' he snarled.

'If you had simply not visited, I would have concluded that you preferred to be elsewhere,' said Mr Nutt. 'However, since your Patronus came to fetch me, I thought that you might want to talk to me.'

'Fine! It's not going to achieve anything, you know. Okay, I'm a human now, so I can talk. But what's the point? Talking isn't going to cure me of the problem of being me.'

'Talking will not stop you from being Severus Snape. However, talking can help you grow into a wiser version of you – or a more foolish version, depending on what you decide to tell yourself. This is why Überwaldian mind-healers believe that it is best for there to be someone to listen while you talk, even if the healer sits out of sight and rarely comments. I can do that, if it would be helpful for you, or we could have something more resembling a normal conversation, if you prefer.'

'I don't want you to be out of sight.' Severus had not, in fact, been looking at Mr Nutt, but now turned to face him, even if he didn't feel like looking Nutt or anyone else directly in the eye. He sat cross-legged on the sand (his now half-drying robe, sticky with sand and salt, almost creaked as he spread out the skirts to cover his groin and legs), and stared down at the beach as he tried to think how to explain what he felt, either to Mr Nutt or to himself.

Author's note: Has anyone guessed who 'older Snape' in the mirror (first mentioned in Chapter 43) really is?