If you are a Malfoy by marriage and a Black by birth, Doing Things the Right Way is bred into your genes, and since genes sometimes prove to be entirely unreliable – you just have to look at Sirius and you'll get my meaning, not that dear Bella didn't commit her fair share of gaffes as well, but let's not go there – a thorough upbringing will compensate for any imperfections targeted pureblood eugenics may not have managed to smooth out. Doing Things Right means doing them the right way; doing them in the right place is equally important, though.

Let me give you an example: Suppose you have impeccable table manners. You never tear chunks out of a dinner roll with your teeth, as if you were a lion tackling a dead zebra's carcass – no, you break off dainty little pieces, without sowing the whole table with crumbs like a diligent farmer. If, however, you employ your perfect dinner-roll-eating technique while leaning negligently against a badly varnished doorpost, you may be able to eat correctly, but you certainly aren't Doing It Right. That would be the case only if you were seated at an impeccably arranged table (on which you are not leaning with your elbows!), clad in elaborate dress robes and making animated conversation with your neighbour.

I know that this probably sounds immensely complicated to your plebeian ears (which I'm not entirely sure you've cleaned properly), but that' how things are, if you're a Malfoy by marriage and a Black by birth.

After Narcissa Malfoy had become aware that she really didn't want to be Mrs Malfoy anymore, because twenty years of being cheated on, being treated like a horrendously expensive but otherwise uninspiring piece of decoration, and being The One Who Was To Blame For It All was enough, and also because she had this secret little affair going, she had to face an even more difficult decision. No, it wasn't the choice between separation and divorce, because she'd opted for a divorce right away. It was the choice of location, of the scene which was to form the perfect backdrop to her declaration, that haunted her dreams and gave her headaches.

The Green Salon would have been perfect. Firstly, because it was just the right shade of green to bring out both her and her soon-to-be-ex-husband's colouring in the most flattering of ways. It also faced East, which was appropriate for the kind of separation that also meant a new beginning. (The Chinese Salon, for example, which faced north, would have been extremely well suited to a dramatic break-up with a note of well-bred gloom. Well-bred gloom also prevented excessive throwing of objects, which would of course be detrimental to the collection of antique china)

The problem that was sending Narcissa into fits of desperation was this: The man she still had to call her husband, if reluctantly, had lately taken to wearing robes of dark burgundy. You didn't need to be a Malfoy née Black to realize that seeing himself in one of the many mirrors, draped on a Louis Seize sofa with jade green upholstery whilst wearing dark burgundy robes, would drive Lucius to distraction. Even a Weasley would be aware that announcing to one's husband, who was looking like a spoonful of beetroot salad on a bed of cooked cabbage, that one was going to leave him, was definitely not a wise move.

In the end Narcissa settled for the library, because a library – and especially one that has grown through the centuries – is always a dignified place, where one feels one has to behave in a dignified manner. She wasn't too happy with her choice, because the library was Lucius's turf, where she felt she was at a disadvantage. Then again, she could console herself with the immensely satisfying thought that she had the upper hand, because she was the abandoner and not the abandonee. That was Lucius's role.

So she entered the library on a bright Saturday morning an hour after breakfast.

'Lucius dear,' she trilled.

Her husband raised his blond head which had been bowed over an ancient tome. The book radiated malice, or was that Lucius? 'Narcissa,' he acknowledged her presence, giving her a slight nod. 'Does it have to be now?'

Usually such a – entirely rhetoric – question was enough to make her turn on her heel and leave the room. Hence his surprise when she replied, smiling, 'Yes, now would be a good time.'

With a sigh that spoke of frayed patience and husbandly suffering, Lucius closed the tome. The pages had barely touched each other when the volume began to vibrate and growl. Lucius, obviously used to this behaviour, froze it with a quick spell. Another flick of his wand, and the book was tightly trussed up in cords.

'Well,' Lucius said, leaning back in his chair and crossing his legs, 'What it is that cannot wait until I have finished with Le Grimoire de Maléfice de Pierre Le Sanguinaire?'

Narcissa wordlessly handed him a stack of papers.

'Shoes again?' He shook his head. 'I think your monthly allowance is generous enough for you not to overdraw your account every time you indulge in one of your whimsical shopping trips.'

Narcissa merely smiled and shook her head.

'Dress robes then? No? Jewels?' Lucius sighed. 'Not another charming little townhouse in Florence!'

Narcissa shrugged, her smile persisting, and made an elegant gesture towards the stack of parchment he still hadn't deigned to look at.

Whether Lucius was intrigued or annoyed was difficult to determine, but he finally glanced at the papers. His brows drew together in a frown, which was as perfectly chiselled as his hands that finally spidered towards the parchments. 'I think,' he said, his tone now a little sharper, 'that I made myself perfectly clear – I handle all business with the family lawyers. Not you, my dear, not the House Elves. Nobody but myself.'

Narcissa managed a demure smile, while watching, with no small amount of fascination, the slow change of expression on her husband's face.

'Have you' – he cleared his throat – 'have you been reading those thrashy novels again, Narcissa?'

Narcissa raised her brows in an unspoken question.

'You certainly don't expect me to remember the author's name, my dear. I am, however, referring to the books you have the highly annoying habit of hiding under your pillow. It seems that you are identifying with the wilful heroine, my pet.'

Narcissa delicately rolled her eyes and shook her head.

'My dear, you seem to labour under the illusion that I am just going to sign these papers, renouncing an explanation. May I remind you that I like to keep what is mine, and do not let go of it easily. If you would be so condescending as to actually enunciate a few words or, dare I hope, phrases of explanation, maybe we will be able to conclude this matter in a way that is satisfactory to us both.' He leaned back and crossed his arms. 'Why do you want to divorce me?'

'Because I no longer have the desire to be your wife.'

'I see. And why now? Why not choose the easy way and divorce me while I was rotting in Azkaban? Or did you still, er, harbour any desire to be my wife back then?'

'Not exactly.'

'Well, that does not come to me as a surprise. But it makes me repeat my question. Why now?'

'It seems like a perfectly good time.'

'What a perfectly inane thing to say.' The grey eyes narrowed. 'You need my signature on these papers, my pet. Humour me.'

'I don't think you are willing to be humoured, Lucius. It would be like trying to humour a shark who wants to bite off my leg.'

'Mmh, yes. But I think even sharks can be humoured. You merely have to offer them something more tempting than your admittedly gorgeous leg.'

'Does that mean you would like me to find you a new mistress of the manor?'

Lucius smirked. 'The idea has merit. But no, my dear, I think I shall see to that myself. For now, I would be perfectly satisfied if you told me about your motives for wanting to divorce me at this point in time.'

'And…' Narcissa twirled a strand of blond hair around her index finger. 'You would sign the papers if I told you?'

'Not necessarily. But a tiny bit of information might keep me from biting off your leg, figuratively speaking. Feel free to translate the metaphor for yourself.'

'What would I have to do for you to sign?'

'Oh, I don't know. That depends on what you will tell me, my pet.'

She had been Doing It Right up till now. Perfect poise, no loss of control, no theatrics. To show how desperate she was would be an unforgivable breach of etiquette. It simply wasn't done. 'Very well,' Narcissa said, her voice as calm and silvery as a moonlit lake in a winter night, 'Very well. I want to be free.'

She wouldn't have expected the genuine smile he gave her. Genuine if he were a shark. 'That, my dear Narcissa, is far too clichéd to convince me. Or rather, the second part of the sentence was missing. Freedom in and of itself is as worthless as money you don't know how to use. So, to which use do you intend to put your newfound freedom?'

'I will have to get acquainted to the feeling, before I make that decision.' It came out more bitter than she'd intended.

'You can most emphatically not fool me, Narcissa. Why not simply tell me that there is somebody else?'

'Why should I?'

'Because, my pet,' he purred, getting up swiftly and walking round the table to stand next to her, 'lying is such a nasty habit. I do not tolerate nasty habits in my wife.'

'Does that really matter, since I won't be your wife for much longer?' she shot back, looking up at him. She hated having to look up at him. 'But if you insist…' Narcissa sighed deeply and turned to look away from him. 'Cousin Etienne and I have become… more than good friends lately. I want to give the relationship a chance, but doing so while being married to you would be extremely bad ton, don't you think?'

'Etienne? Are we talking about Etienne Malefoi, who attends every bal masqué disguised as a flobberworm, because all he needs to do is crawl on his belly and pretend to be marginally more intelligent than he actually is?'

Narcissa nodded and shrugged, affecting an air of supreme pique.

'Well,' Lucius said after a while, 'at least he is family. Unless you decide to have children, I think…' He crossed the room and looked at the enormous tapestry that covered a large part of the far wall, showing a family tree of equally impressive proportion. The motto floating above it read 'Ma Volonté Est Mon Droit'. Lucius studied the tree for a few seconds with his head slightly cocked to one side. 'Just as I thought,' he finally said, 'if you do not procreate, which I fervently hope you won't, given the history of madness running though that particular branch of the family, I am his sole heir.' He turned back to face his wife and smirked. 'He may be twenty years younger than I, but given his habits…' He quickly strode back to the desk and signed the papers with a flourish. 'And now,' he hissed, 'get out of my sight.'

Narcissa managed a lone tear that gracefully meandered down her cheek. She merely nodded and hurried out of the room.

Fifteen minutes later, she was in one of the Leaky Cauldron's guestrooms, pinned to a bed by the supple but well-muscled limbs of Kingsley Shacklebolt, giggling and frantically trying to get out of her robes.

'He really believed you?' Kingsley asked in between kisses.

'I suppose he did. Otherwise he would never have let me go. That greedy, possessive bastard.' She managed to wriggle out of her clothes. Her legs – Lucius had not been exaggerating when he called them gorgeous – snaked around Kingsley's thighs. The kiss became a little more heated.

When her lover's mouth descended to her breasts, Narcissa cast a thorough look at the snug but rather shabby room. The surroundings were perfect. Finally, finally she was able to say it, the right words in the right setting.

'Fuck me, darling!' she moaned. That was what Doing It Right Meant – on every possible level.