No-one in Raveloe trusted the strange young newcomer with the hippyish black hair.

At first, they weren't even sure what gender the incomer identified as. Obviously, they were biologically male, but they not only had long hair – which wasn't so unusual for the 1970s – but habitually wore a witchy black dress. It wasn't until some months after arriving in summer that Mr Snape, as the neighbours now knew him to be, bought a pair of flared jeans at the parish pre-Christmas jumble sale, and cut down his – dress? robe? – into something more like a long, high-collared jacket.

Raveloe had grown from a farming village in the time of the Napoleonic Wars to something more like a small market town by the latter half of the twentieth century. In the 1940s, the child population there had been swollen by children evacuated from the bombing raids on the big cities, and the older of these children had spent weekends and summers working on the farms alongside the women and any of the men who could be spared from military service, and some of them had loved rural life enough that they had moved back there as adults and married the villagers who had been their schoolfriends and childhood sweethearts. So, instead of falling apart as its young people left and its farms became more industrialised and needed fewer workers, like so many villages, it had a thriving population who weren't all related to each other, and a High Street with enough custom to support not only a grocer-and-post-office, but a greengrocer, a baker, a butcher, and even a hardware shop and a hairdresser with a zero-packaging wholefoods co-operative at the back (if you didn't mind eating lentils and prunes that tasted of hair-oil), in addition to the weekly farmers' market.

And then there was Mr Snape's herbal remedies shop, in the building that had once been the cheese shop. Only a few people from Raveloe ventured in, and he seemed to do most business by mail-order, via adverts in newspapers and magazines. It wasn't exactly a normal pharmacist, but it wasn't exactly a normal witchy alternative shop, either. It didn't sell crystals, or tarot cards, or model dragons or fairies. People who asked to have their fortunes told were informed that 'Most so-called seers are nothing but frauds – and besides, have you any idea how much damage it could do, to hear part of the future and misunderstand it?' People who asked for a love-spell got the riposte, 'And do you expect to keep drugging your victim for the rest of his life? Or are you deluding yourself that if you condition him to "love" you for long enough, he'll be so brainwashed that he could actually start to love you?'

On the other hand, people who came with health problems that the doctor hadn't been able to diagnose, or had told them were untreatable and terminal, got medicine that came in the form of foul-tasting potions rather than neat little pills, but worked. Instantly. Almost like magic. Of course, as modern, educated people, they all knew that there was no such thing as magic, and that 'spells' were just something to make life a bit more fun, not far different from a kids' Hallowe'en party. Someone like Severus Snape, who behaved as though he actually believed in magic, was alarming – although, admittedly, he was very young, probably still a teenager, just going through a phase.

Severus had left school when he was seventeen, one term into his sixth year. The summer that he was sixteen, he hadn't gone home for the holidays. What would be the point? It wasn't as if he particularly wanted to see either of his parents, and Lily didn't want to hang out with him any more. Instead, he had rented a room in Diagon Alley and spent the summer working in the apothecary's shop there. If he ate sparingly, he still had gold left over after buying food and paying his rent, and by the end of the summer he had actually been able to buy himself a wand that chose him, instead of using mum's old wand, and opened a Gringott's account to save the rest of the gold.

He had hoped that by September, Lily might be willing to forgive him, if he clearly wasn't friends with Avery and Mulciber or any other wannabe Death Eaters. She didn't. He didn't have any friends any more. Even Professor Slughorn, although he still praised Severus's work in class, and still let him use the lab for doing experiments after classroom hours and at weekends, didn't invite him to parties any more. Severus didn't complain. He kept to himself and studied.

At Christmas, he explained to Professor Slughorn that he was leaving to start work in the apothecary's shop, but that he was going to keep studying, and would like to return in a year and a half to take the exams.

Professor Slughorn had looked deeply worried – not just sad that a bright pupil was dropping out of school, but alarmed, as though saying, 'I want to work in a shop,' was equivalent to 'I want to sell my soul to the Devil.' Severus was not to know, until many years later, that Tom Riddle, though he had completed his education and had been Head Boy, had worked in an antiques shop after leaving school. But he had known that he should say something to reassure his favourite teacher.

'It's not that I don't like learning,' he had explained. 'It's just – someone said to me that with the people I'm friends with at school, I'm on the way to turning into a Death Eater. And I don't want that. So I think it's best if I leave now.'

'But, dear boy – it doesn't have to be like that! If you do well in your NEWTs, you could start training as a Healer at St Mungo's in a couple of years!'

'I told you, I'm coming back to take the exams, and then I can decide what to do. I just don't think it's a good idea to be here any longer.'

Professor Slughorn had hugged him and told him he was a good boy, which wasn't something Severus heard often. He had told Severus to check with his other teachers what textbooks he would need, but Severus had already done that anyway, at least for Alchemy and Charms – there hadn't been much point talking to the current Defence Against Dark Arts teacher, considering that every successive teacher introduced a different syllabus and most of their lessons had little relevance either to defending yourself in real life or even to getting through the NEWT examination, and he had decided to drop Astronomy, which, while interesting, was probably the least essential subject to learn if he needed to combine studying with working.

Studying had been much easier with a rented room of his own, without having to worry about who might hex him next and whether they would actually try to kill him or just humiliate him. He had returned to school, aged eighteen and a half, to take the exams, and left with Outstanding in all four subjects. By the following year, he had saved enough gold that he was ready to start his own business, so he converted most of his gold into Muggle money, and moved to a Muggle small town where nobody had heard of Hogwarts, Diagon Alley, or Voldemort.

Raveloe didn't have much poverty, or at least, it didn't have much of a divide between rich and poor. In the early 19th century it might have had what remained of the old squirearchy, but by now, the larger and more gentlemanly houses had been converted into shared houses, blocks of flats or old people's homes, and might have been turned into hotels if there had been more in the area to attract tourists. The biggest difficulty in organising a jumble-sale was not that people didn't want to buy second-hand clothes but that they were still wearing their old clothes, at least for relaxing at home, doing the gardening or going for walks. While there were quite a few people with learning disabilities who would have struggled to find work in a more sophisticated town, in Raveloe their neighbours found them odd jobs that they could do, even if they didn't do them very well, because after all, they were family, part of the oldest families in the village.

It didn't, generally speaking, have many tramps and beggars, mainly because they had more chance of making a living by asking for spare change from tourists in the cities. Maggie Farren was one exception. On New Year's Eve 1981 she made her way to Raveloe, with a small child in a backpack on her shoulders. She had seen some of the adverts for Snape's Herbal Remedies in the papers, and she was convinced that this was no ordinary alternative practitioner. This, she was sure, was a real wizard, like the handsome wizard she had spent a night with some two years previously. And as there couldn't be many wizards around, probably they trained together and knew each other, and maybe this wizard might know the real name and address of the father of her child. There couldn't be many men with such a distinctive appearance, after all.

She might have made it. Unfortunately, since the effects of the delicious-smelling drink her boyfriend had given her had worn off, she had craved the giddy, delirious feeling that it had given her, and had been desperately trying to replicate this with whatever she could drink, smoke, snort or inject. She was feeling too ill to walk, now that the last dose was wearing off and withdrawals were setting in. Another injection would help her feel better. She sat down in a convenient shop doorway, took the backpack off and laid her daughter down by her side, while she fumbled for a twist of powder. Not long afterwards, she fell asleep. Her daughter, who was hungry and knew from experience that it was no use asking mum for food, wriggled free of the straps that were supposed to restrain her in the backpack, and set off to forage.

Severus wasn't in that night. His body was lying on the bed in his flat above his shop. His mind, however, was trying out an obscure spell that he had read about. It was one that students weren't supposed to attempt without supervision, but no teacher in Hogwarts had taught anything like it. He spread out his consciousness, trying to find the mind of a life-form. December wasn't a good time of year to try the experiment – so many creatures were either hibernating, like bats and hedgehogs, or had flown to Africa, like swifts and cuckoos. He managed to find a fox outside on the pavement, and tried to decipher the fox's consciousness and thoughts, and how it interpreted the things it saw and heard and smelled. It was more interested in foraging for scraps than hunting, at this time of year, when game was scarce, though it knew that pet-owners didn't always lock their guinea-pigs' hutches in the shed.

It smelled a human, and wondered whether this was a good thing or not. Humans on horses with dogs sometimes chased foxes, and humans with guns sometimes shot them, but some humans put out food. And this was a very small human, after all. Ah, here was food…

Severus forced himself back to his own body, sat up trying to ignore his craving for rabbits, switched on the light, and grabbed an electric torch from his desk drawer. He banged on the window and shouted to frighten the fox off before it could harm the child, then made his way downstairs. How near was the child? He wanted to rush out straight away, but forced himself to pull on a pair of rubber boots and put on a coat over his nightshirt, bearing in mind that it was snowing outside and he might have to search for quite a while.

The church clock struck midnight and people began letting off fireworks in their back gardens, but Severus paid no attention. He swept the beams of his torch up and down the street, until he found a small child picking her way through a paper package of fish and chips which she now didn't have to share with the fox.

Still trying to focus on thinking like a human rather than a fox, Severus wondered where the child had come from. Who would let their children run around loose at this time of night and this time of year? Had this one been allowed to get up and come downstairs for a firework party? But it didn't look like any of the children he remembered seeing around here. Apart from anything else, it was blonde, when most people in the area had brown hair. In fact – he peered at the child more closely by torchlight, which the child ignored, still focused solely on the chips – with its very pale blonde hair and sharp, aristocratic-looking, rather elfin features, it looked very like someone he knew.

'Where's your mum?' he asked. 'Or your dad?' The child still ignored him – maybe it was deaf? No, it winced at the sound of a particularly loud firework. It just wasn't interested in humans.

Severus tried shouting, 'Hello? Has anyone lost a child?' Then he realised he was being ridiculous. There was enough snow to show a trail of small footprints. He picked up the child, who squirmed in protest, and followed the trail back to a figure lying very still, slumped in the snow. He checked. No pulse. No breathing. Almost certainly dead, but – he really should have trained as a Healer. In the meantime, he needed to get an ambulance, just in case. And a Healer, or the nearest that Muggles had. Dot Winthrop, who lived next door to him, was the district nurse. She'd do.

Still carrying the child, he walked to the Winthrops' and rang their doorbell loudly. Mrs Winthrop's husband Ben, the car-and-tractor-repairman, opened the door cheerfully, a glass in hand. 'Hello!' he said. 'Come to join the party?'

'No. I need your wife. And your phone. I need to call an ambulance. There's a woman collapsed in the snow.'

'Your phone not working?'

'No.' He had stopped paying the bills, as he simply didn't do enough business by phone for it to be worth it.

'Well, fine, use ours.' Ben Wintrop gestured to the machine sitting on the hall table, and, while Severus dialled 999, went to find his wife, who was bandaging the arm of a guest who had burned himself on a firework.

The child by now had wriggled free of Severus's grip and, without looking at either of the men, went to investigate a table full of snacks. 'Wait!' said Severus indignantly. 'You don't just help yourself! You say, "Please may I have something to eat?"!'

The child, sensing his indignation, dropped to its knees and curled into a ball, as if expecting to be hit. Severus remembered that feeling all too well – not knowing what, exactly, adults were angry with him about, but knowing that punishment would come. He knelt down beside the small figure. 'I didn't say that you couldn't have food,' he explained, more gently. 'I'm not going to hurt you. But you need to say "please". Do you understand? Can you say "please"?'

''Lease,' said the child. Severus reached down for a mince pie and handed it to the child, who devoured it ravenously.

In the meantime, Ben took over the phone call, asking Severus for confirmation of details. Dot went out to find the patient, carried the desperately thin and light woman indoors, and laid her on the living-room floor, where she and a female friend took turns for one of them to attempt CPR while the other removed the woman's wet clothing and covered her in a warm, dry blanket.

Long before the ambulance arrived, it became clear that the woman – Margaret Farren, according to the damp cheque-book and cheque guarantee card in her coat pocket – wasn't going to recover. While Dot's friend continued to pound on the woman's ribs just in case, Dot came over to have a look at the child, who was starting to relax a little.

'We'd better get you into some dry clothes, too,' she said to the child, who did not look up at her. 'I'm sure I've got some old clothes upstairs in your size. Do you use nappies, or do you use the potty like a big person?' No response. 'Well, you could probably do with a nice warm bath, anyway, and then bed.'

'What are you going to do with this child?' Severus asked. 'Is it – he – she – going to go to an orphanage?'

'Oh, no! Social services try to place children with foster families where they can, especially little ones. I used to be a foster-mum while my own children were little and I was at home with them anyway, but now I'm back at work, it's not so easy. But if they can't find anyone else, I'll see if I can get some time off work to look after this one until they can find the child's family, or place her with a long-term foster family.'

I think I might know this child's father,' said Severus. 'I'll make enquiries.'

'Really? That'd be wonderful, if you could.'

'I will.' Apart from anything else, if this was a magical child, it wasn't safe to let them grow up in a Muggle family. Especially not with the Winthrops – not that they weren't kind people, but Dot Winthrop was a Christian. Only the week before, she had been round to Severus's shop to offer him some home-made mince pies and ask him whether he wanted to come to the carol service at the local church. If she was still fostering this child when it started showing signs of magic, what if she decided the child was demon-possessed and needed to be exorcised?

Since the child seemed more confident around Severus than anyone else, he helped Dot to bath it – or her, as it turned out. Dot sighed at the rash around the little girl's bottom when her long-soaked nappy came off, and asked Severus to fetch a tub of ointment from the bathroom cabinet. He did so, and promised to fetch some of his own salve once the child was settled. In the meantime, he helped to clean her up, put on a fresh disposable nappy and dressed her in a snuggly outfit with teddy-bear ears. 'This used to be my Aaron's, when he was this little one's age,' Dot explained. 'I'll have to tell him in the morning that he's got a foster-sister again. I wonder what her name is? There's no label on any of her clothes.'

Severus went home to fetch the salve, then went home again, but not to sleep – not just yet. He checked the latest edition of The Daily Prophet. Since He-Who-Must-Not-Be-Named had been defeated, the Boy Who Lived had been fostered by his grandmother, Augusta Longbottom, following the deaths of his Auror parents Frank and Alice, but Lily and James Potter had expressed an interest in adopting him as a brother for their own son. Lucius and Narcissa Malfoy had been cleared of all charges of Death Eater activity after it had been established that they had been under the influence of the Imperius Curse and had no memory of the past two years. There was a picture of them, smiling and waving, Narcissa holding a little boy in her arms who looked strikingly like the little girl Severus had just put to bed.

Severus snorted. He didn't believe the amnesia story for a moment, but it could provide Lucius with a way to save face, in public if not with Narcissa. And it might be good for Draco to have a sibling. Like the Potters' son, if he remained an only child he would probably grow up to be as much of a selfish spoilt brat as James Potter himself – or for that matter Lucius – had been.

Severus took out a quill and a piece of parchment, and began as bright and newsy a letter as he could make it sound, filling Lucius in on what had been happening over the time he had 'forgotten'. He concluded:

'We have had a couple of new arrivals in this Muggle town lately: Margaret Farren and her daughter, who is around the age of your Draco. You may not remember the Farrens, but I think Margaret remembers you. Are you interested in re-establishing contact?'

He wondered why he was doing this. Was it out of spite, because Lucius, who had seemed friendly at first, had led him into bad company and taught him attitudes that drove Lily to break off friendship with him? Was he trying to punish Lucius by making Narcissa realise he had cheated on her? Or was it because he cared about the nameless girl and wanted her to have a wizard father – even a Death Eater wizard father, even a selfish wizard who had seduced and abandoned her mother and concealed her existence from his wife – rather than be an orphan? Or even both?

He gave the letter to his post-owl, Zephyr, to deliver. Severus wasn't enthusiastic about animals, but an owl was a much more essential communication device than a phone, and even if a Muggle post office could have found Malfoy Manor, the exchange of letters would have taken perhaps a week. Zephyr flew off into the night and returned the following day with a cheerfully bland letter from Lucius which made no mention of the Farrens.

In the meantime, he called in to see how young Miss Farren was getting on. Dot looked dejected, but tried to be positive about it. 'Well, she's not going to starve, anyway – I woke up this morning to find everything pulled out of the fridge! Some children as neglected as that, they just lose the will to live – I saw one once who'd just starved to death when his mother went out partying for a week and forgot about him. Hadn't even thought to cry out for help, he was just so used to being ignored. But, well, she's emotionally in as bad a way as you'd expect. Doesn't look up, doesn't talk, doesn't make a sound, doesn't even cry…'

'Is that bad?' Severus asked, surprised. He knew that when he was young, making a sound got him into trouble.

'Well, of course it's bad! Any normal person would cry, if they've lost their mum and woken up in a strange house. But this one, she barely had her mum anyway, so she grew up thinking that's normal, not to be loved.'

'If – if no-one can find her family, can I keep her? Foster, or adopt her, I mean?'

'I don't see why not,' Dot said. 'She seems to trust you more than anyone else. You'd have to phone a fostering agency and tell them you're interested in fostering, and then they'd spend a few months coming round to visit you to check up on you and make sure you're safe to look after a little person, and if they think you're all right, they'll send you on a training course. It mostly takes about five or six months – mine did, anyway. I dunno, maybe they'll think it's a bit odd, a single man wanting to take on a little girl…'

No! He HAD to keep her! For a moment, Severus wanted to Confund everyone, make them believe this was his daughter, before they took her away and had her adopted by some Muggle family who wouldn't understand her and might lock her away in some mental hospital when they decided she was a freak.

No, when you started seeing Muggles as the enemy, or as animals to be manipulated, that was well on the way to Death Eater thinking. He'd keep it as a last resort. In the meantime, if he was going to live among Muggles, and show the little girl how to grow up passing as a Muggle, he'd need to see whether he could win while playing by their rules.

'What is the child's name?' he asked.

'I don't know. There wasn't a name on her clothes, and she doesn't seem to have any toys or anything. I've tried saying different names to her, but she doesn't answer. Maybe you could give her a name?'

'Eileen,' suggested Severus. For a moment, the girl looked up at his voice.

'Eileen Farren it is, then,' said Dot happily. 'Bit old-fashioned, but it'll do. Thanks for that salve, by the way,' she added. 'It worked like magic.' She looked Severus in the eye and for a moment he could have sworn that she knew exactly what he was.

So, for the next six months Dot and Ben juggled work schedules so that they could foster Eileen, and Severus came round to help look after her every day, and when he had managed to satisfy the fostering agency that he wasn't a pervert but just someone who was interested in long-term fostering with a view to adoption, and that he had sufficiently child-proofed his home including keeping his owl confined in a suitable aviary, Eileen moved in with him.

She made progress, if very slowly. She rarely made eye contact, and if she didn't look, it usually meant she wasn't listening – except when you assumed she wasn't, in which case it would turn out that she had heard and understood every word you said. She didn't trust most people except Severus and Dot, and never wanted to play with other children, except Dot's son Aaron, six years older than her, who continued to regard her as his little sister even after she moved next door. Except for occasionally echoing other people's words, she barely talked until she was three, at which point she started talking in full sentences to explain what she didn't like, such as being kissed or cuddled or tickled. Dot said that some children just were like that, and didn't enjoy touching, but (she added in private to Severus) that she thought Eileen just wasn't used to it, because she had been so neglected when she was little, and that she might change her mind when she was ready.

Dot turned out to be right, and the summer that Eileen was four, she started to initiate hugs, running to wrap her arms around Severus's legs and ask to be lifted onto his lap for a cuddle.

Unfortunately, she was supposed to start school in the autumn, and one of the strictest rules was that staff must under no circumstances, other than giving first-aid in the case of an accident, ever touch a child, in case they were accused of abuse.

'Why should she have to start school yet?' Severus demanded. 'I didn't go to school until I was five, did you?' And even then, he suspected his mother might have preferred to homeschool him, so that nobody should suspect he was a wizard, if it hadn't been for the fact that going to school meant he got free school meals and milk rations. It had also meant that the school nurse made sure he was up-to-date on his vaccinations, when his mother had never heard of vaccines and his father hadn't even realised that healthcare was now free for all citizens including women and children, as free healthcare had only been offered to working men when Tobias Snape had been a child.

'No, but they expect everyone to start at four now. It's not right, I know – it should be playgroup if anything at that age, and Eileen isn't even ready to cope with playgroup, is she? But if she waits another year, they'll make her skip Reception and go straight into Year One, and she'll have even less hope of making friends if everyone else already has a best friend.'

'She'll have even less hope of making friends if she starts school at four when she won't look at other children and can't remember their names and everyone decides she's a freak,' retorted Severus through gritted teeth. 'Believe me, it's just as easy to be lonely in a school full of children as it is to be lonely at home. Eileen doesn't even want friendships with other children yet, apart from Aaron. She just wants to know that I'm not going to abandon her the moment she turns her back!'

He took Eileen into school with him on a visit, to show her around and to explain to the Headmistress and the teacher of the Reception class about Eileen's situation. The Head suggested a compromise. Eileen could come into school just for mornings in the first year, and she could have a teaching assistant to work one-to-one with her as she had special needs, but Severus could come in with her and help some of the other children practise their reading, so that Eileen could see that he was in the classroom and that she could go to him if she needed reassurance. And Aaron, although he was in the Juniors and in Year Six, had special permission to come into the Infants' playground to help organise games at playtime and make sure that Eileen wasn't excluded.

By the end of her first year, Eileen had made huge progress. She could read better than most of the class (because she wanted to be one of the good readers so that her Daddy could be proud of her), but, better still, she had enough friends that she could have an actual birthday party, and she announced that when she went into Year One, she wanted to walk to school with her friends and stay the whole day, and not have Daddy with her in the classroom.

Severus tried to feel proud of her and not sorry to lose her. But equally, he didn't lose contact with the school. Being a classroom assistant, helping children practise reading Gobbolino the Witch's Cat and A Dragon in Class Four, even while they had no idea that witches and dragons were real, had been fun. So had helping to teach singing, and playing a scary evil wizard in the pantomime that the teachers had put on as a treat for the children at the end of the autumn term. The Head was happy to let him continue to come in part-time as a voluntary helper, coaching music and drama, but just not arriving at the same time as Eileen or teaching the class she was in. After all, if she did start behaving oddly or having a panic attack, they could always fetch him.

Severus didn't hear Eileen laugh until she was six. She had been to a Christmas party where the vicar, dressed as Father Christmas, had given all the children presents. Eileen's had been a pink plastic toy that looked like a hybrid between a unicorn and a pegasus made by a Muggle who had never seen either. The day after the party, Eileen had gone next door to play with Aaron (now at secondary school, but still patiently willing to play with his little foster-sister), and Severus could hear the two of them giggling together. His heart warmed – and then his stomach lurched, as Eileen's pegacorn flew over the fence. It wasn't thrown – it flapped its wings and soared like a real flying horse, and tossed its head and butted the air with its tiny stubby horn like a real unicorn, landed with all four hooves on Severus's shoulder and…

'Can you get her to come back again?' Dot called, and the little toy took off again and flew back across the fence.

Of course, Eileen's magic would have to come out in the presence of Muggles. But by the look of it, she was one of those rare children who could control her magic from an early age and use it for fun, like Lily, instead of just reacting magically when she was angry or frightened, the way Severus had. So why didn't she have the sense to wait?

Severus went next door to try to limit the damage. When he rang the doorbell, Dot let him in. 'Good to see you, Severus,' she said. 'Tea?'

'Uh, yes, please…'

Dot put a teabag in a mug, and ran cold water over it from the tap. Then, holding the mug in one hand, and checking that the children were still happily playing outside and not watching her, she stuck her other hand in the fire and channelled the heat through her until the water in the mug boiled and the tea was brewed to perfection (or as near as teabag tea ever got).

'You're a witch?'

'That's right.'

'But – I thought you were a Christian?'

'I am. I trust God, and if They made me magical, They had a reason for it.'

'Does Ben know?'

'He knows I'm a bit strange. He doesn't know a word for it, particularly. But we know we love each other, and that's the main thing.'

'Did you – I don't remember you from Hogwarts…'

'No, I'm a hedge-witch. My granny taught me, in the evenings. And in the daytime, I went to the same school Aaron's going to now, took my CSEs, and left at sixteen to train as a nurse in a Muggle hospital. My granny always said schools like Hogwarts don't make witches, they make women wizards, and that witches need to be where Muggles need them, not hidden away in magical villages. She said her granny's granny never even went to a village school, let alone Hogwarts, couldn't even read, and it didn't stop her being a good witch, and the village was proud of her then, same as it was proud of my granny.'

'That's one way of looking at it,' said Severus dubiously. His mother had been a witch living among Muggles, after all, and it hadn't enabled her to be a force for good in the community. She had just been an unhappy woman who didn't understand Muggle culture and was under her husband's thumb, and couldn't leave because she didn't know what options she had. But Dot wasn't like that at all.

'Do you want Eileen to learn from you?' he asked. 'To be your apprentice?'

'No, not unless she wants to. I reckon she'll be the girl-wizard sort of witch. But it's another five years – well, four and a half now – until she has to decide.'

Eileen, by the time she was eleven, emphatically did want to be the girl-wizard type of witch. When her letter from Hogwarts arrived, she was almost bursting with excitement as she waited for Severus to take her to Diagon Alley to buy her school supplies – and to show he the shop where he had had his first job, and the house where he had had his first lodgings. Some of his favourite shops from when he was young had disappeared, but Flourish and Blotts' bookshop was still there, as was Florean Fortescue's Ice-Cream Parlour, where they sat down for a break after buying Eileen's wand.

Lucius and Narcissa came in and sat down at an adjoining table. They looked much older and sadder these days, although Severus knew they were only in their thirties.

'Ah, hello,' Narcissa began. 'Are you getting ready to go to Hogwarts?'

'Yes!'

'What House do you want to be in?'

'My dad was in Slytherin, and so was my gran,' said Eileen. 'I'm named after her. But my dad says all the houses are good, except that most Gryffindors are mental, but some of them are all right.'

'Is this your dad?' Narcissa asked.

'Yes. He's been my legal dad since I was seven, but he's been my foster-dad since I was a baby, when he found my mum dead in the snow.'

'Do you know who your real father – your original father – was?' Lucius asked.

'No. But I don't like him. 'Cause he left my mum to die. Anyway, Severus is the best dad in the world.'

'Are those – second-hand books and robes?' Lucius asked. Severus bristled. His potion business didn't do badly, but it didn't make a huge amount of money either, and the money he had been paid to foster Eileen had stopped once he formally adopted her as his daughter.

'Yeah. They're the right editions of the books, we checked,' said Eileen cheerfully. 'My dad says they don't change every year. And I'm growing really fast at the moment, so there's no point getting new robes. Dad's really chuffed about it, 'cause when I was three, for a whole year I didn't grow at all. He says it was my magic stopping me growing 'cause I was frightened that he might not like me if I stopped being a baby, but once I was sure I was safe, I could start growing again. But he reckons I'll be tall when I've finished growing. We did get my wand new, though,' she added. 'It's hazel wood and unicorn hair. Do you have any kids?' she added.

'No,' said Narcissa. 'We had a little boy once – he'd have been your age. But he died when he was five. A dragon that he'd been teasing ate him.'

'Well, he shouldn't tease it, should he?' retorted Eileen. 'No-one should be horrible to animals. Like that poem about the boy and the lion at the zoo.'

'I'm sorry for your loss,' said Severus, and he meant it. He agreed with Eileen, but even so – he could only imagine how he would have felt if Eileen died.

'So, we were wondering – if you've been adopted once, how would you feel about being adopted again?' asked Narcissa. 'If you could come and live in a house with elves to look after you, and white peacocks, if you like animals? And with a married couple adopting you, so you could have a mother and a father?'

'Nah,' said Eileen. 'I don't need adopting now. I've got a dad. And I had a mum. And Mrs Winthrop next door is like a mum to me, too, and her Aaron is like a brother to me. I don't need any more family.'

'Eileen…' Lucius began.

'Are you going to tell me you're my real dad? Like in The Empire Strikes Back, where Luke thinks Darth Vader murdered his dad but then he finds out that Darth Vader is his dad?'

'Uh – yes,' said Lucius, sounding confused.

'Well, you're not. I'm a half-blood from a Muggle town, like my dad. Can we go now?' she asked Severus, despite not quite having finished her ice-cream. 'I want to show Mrs Winthrop my wand.'

The day after Eileen had set off for Hogwarts, one of the school owls brought Severus a letter. Eileen wrote excitedly about the school, her classes and her new friends, and asking whether her new friend Neville could come to stay with her for the Christmas holidays. Finally, after signing her name with a row of kisses, she added, 'PS I'm in Hufflepuff. I hope that's okay. Some of the other students said Hufflepuff is just for people who can't get into the other Houses. But Neville is in Gryffindor and he is sad because he wanted to be in Hufflepuff with me.'

Severus picked up his quill and began to write: 'Dearest Eileen, congratulations on being chosen for Hufflepuff. Believe me, you are not there because you don't qualify for the other Houses, but because you are loyal, hardworking and a good friend, and I am deeply proud of you. But please know that I would be proud of you even if you were in Gryffindor, because you would still be the best daughter in the world, and I would still be the luckiest dad in the world. And because you are loyal and kind, you will still be Neville's friend, and yes, of course he is welcome to come and stay at Christmas. I look forward to seeing you both in December.'