'I don't want to be Richard of Gloucester!' protested the short, ugly teenager.

'That's just as well,' I said.

I had feared that he would have decided that he did want to be Richard, that he was jealous that Richard had got there first by being written 394 years earlier, and that the best solution would be to murder Richard and assume his place in the play.

We had learned not to billet large batches of Generics in a story containing a strong character, after the Danverclone disaster. However, individual Generics could imprint just as easily. This one, having spent a single night in emergency accommodation in the backstory of Richard III before moving on to his assigned foster home in a Georgette Heyer romance, had woken up as a short, crippled hunchback with a burning ambition, deep-seated insecurities, and a self-mocking sense of humour.

Of course, if he had imprinted strongly enough, it was quite possible that he did want to murder and replace Richard, and had enough sense not to admit to that except in solitary monologues. But I wasn't sure he was likely to have grown that sophisticated in a single night.

'What don't you like about being someone like Richard?' I asked, hoping to encourage – no, not encourage the forming of a sense of self; this Generic was already getting there without any help from me. I felt quite excited. This one was clearly planning on being an A-class protagonist, which was more than I had ever been able to aspire to myself. As an instructor at St Tabularasa's Training College for Generics, I had never really needed more individuation than 'cares deeply about his students'. I had chosen my gender – male – on the toss of a coin, and my name – Dr Fnorp – because nobody else wanted it.

'I don't want to be a villain,' he said firmly. 'Especially not a Villain Protagonist usurper king who murders his way to power. I'd rather be a hero who triumphs over adversity, perhaps adversity from people suspecting he's an evil usurper when in fact he's a loyal feudal lord who rescues the king. I don't want to be a murderer who manipulates his victims' widows into marrying him. I want to be a romantic who longs to find true love – and possibly happens to fall in love with the widow of someone who died in close proximity to me under suspicious circumstances,' he added with a disarmingly mischievous grin.

If this was true, then he hadn't imprinted on Richard; he had exprinted. 'I think you could have a good career ahead of you,' I said. 'You've got a lot more to learn, of course, when you start your classes at St Tabularasa's.'

'When can I start work experience placements?' he asked. 'I'd like to explore as many genres as possible. Historical Fiction was interesting, with all the political chicanery in the plot, but I'd like to explore Crime, Political, Spy, Thriller, Military, Adventure, Science Fiction, Fantasy, Comedy, Romance – and more of the areas of Human Drama, like Family, Internal Struggle and Coming of Age…'

'Work experience generally comes a bit later,' I said. 'First, you need a bit of time to settle in with the host family you'll be staying with, over in Romantic Comedy. There's a boy your age – a Classics geek, but he's also interested in horse-riding and he might teach you – and his older sister and her husband. Then you'll go to classes when term begins, starting with…' (I tried to think rapidly. He clearly didn't need introductory courses in concepts like humour, irony or choosing a gender) 'well, choosing a name, for example.'

'Oh, sorry, didn't I introduce myself? I'm Miles.' I was fairly sure that he had made this up on the spur of the moment, so as not to delay his training any longer. But the fact that he could do this was an excellent sign.

Inevitably, Miles was trouble. Not at home – he loved his new siblings, or at last Aubrey, Venetia and Lord Damerel, and fortunately Aubrey and Venetia's older brother preferred not to visit the narrative, as he disapproved of the plot resolution. But experiencing family made him all the more eager to be a qualified character as soon as possible, so that he could be written into a story where he could have a real family of his own. I hoped he wouldn't be disappointed. Outside Children's Fiction, Human Drama, and the Mother-In-Law Jokes region of Comedy, most protagonists – especially in action roles such as secret agents and detectives – didn't have parents or siblings, and were doomed to a tragic bereavement if they dared to fall in love to an extent which pointed towards marriage and a happy ending.

Still, the question was whether Miles would even survive long enough to be disappointed. When he accepted an invitation from some of Damerel's friends to visit another Heyer novel, he talked the villain out of dying of a broken heart when he frees the heroine to be happy with her true love, and instead encouraged him to change his name and apply for a job as the hero of the next novel to be built. Most of the other characters happily joined the ex-villain in this, and he and his new wife went on to populate sequels with several generations of descendants.

Of course, poor Miles had been too young and naïve to foresee the consequences of having a friendly conversation with a depressed ex-villain. But when he learned about Fiction Infraction trials and the strong likelihood of being reduced to text, he panicked and fled, zipping unpredictably from one genre to another. Fitzwilliam Darcy eventually brought him back after catching him sheltering in an unobserved corner of Pride and Prejudice while the Jurisfiction agents on his case had been still combing the Discworld for him.

Horace Rumpole managed to get Miles off with a suspended sentence, as he was underage. We had been worried by the news that the trial was to take place in Henry V, in view of Henry's new-found zeal for stringent adherence to the law even when it meant hanging his old friends for petty theft. But as it turned out, the King was quite relieved to have a defendant before him who wasn't an old drinking buddy of his, whom he could be merciful to without being accused of favouritism.

After Miles had endured a year of theoretical training classes without a practical assignment, I could finally give him some good news. 'They're looking for a skilled Generic to provide two weeks' holiday cover in The Princess Bride. Are you interested?'

'As you wish.'

'Not Westley – not this time, anyway. This is a placement covering for Vizzini. But I need you to stay in character, okay? No ad-libbing, no changing the plot, no surviving when you're supposed to be poisoned, no having a change of heart and helping Buttercup escape, no tricking Prince Humperdinck into getting himself killed in battle, and definitely no turning Vizzini into a sympathetic character who cares deeply about his henchmen. Just stick to the script. I know you don't plan to be a villain, but if you're going to be a secret agent, you'll need to know how to play a villain convincingly. Think of this as practice.'

Of course, things didn't go according to plan. 'I sding to plan. 'tayed in character!' Miles protested. 'I resisted every temptation to play Vizzini with even a hint of honour, conscience or sympathy.'

'You emphasised his nastiness to such an extent that Inigo and Fezzik felt no loyalty towards him, had no motive to resurrect him, and decided to resurrect Westley instead,' I pointed out. 'The real Vizzini isn't happy at having his role in the story curtailed.'

'So he should have paid more attention to his co-characters. Inigo and Fezzik were already fed up with working with him. And this way, even with the cliff-hanger ending, they at least have some chance of things turning out well. At this rate, they and Westley and Buttercup – and any children any of them might have – even have the chance of a sequel together.'

'Sequels, yes,' I said. 'You've got a fair few ideas for what you want to be: a soldier and a secret agent and a detective, but also, I seem to recall: "The hero of a romantic comedy who is deeply in love, a loyal friend and a loving brother, but arrogant and manipulative in a way that justly infuriates the poor but proud heroine, until eventually they reach a happy ending in the most absurd possible way." Do you still want that, or was it just a whim from your experiences in Pride and Prejudice?'

'I've wanted it since I first set foot in Georgette Heyer,' said Miles. 'But I'd also like to do some serious novels about identity and conscience, not just thrillers and romance.'

'So you're hoping to be the hero of a series – and one that moves quite freely between genres,' I said. 'Have you thought about what range of ages you'd be willing to live through?'

'I'd like to live all the way through, like an Outlander,' said Miles. 'Right from childhood through to – well, old enough to watch my children grow up, anyway.'

'Fine,' I said. 'In that case, if you want to do things the Outlander way, you can try starting right at the beginning. I want you to put in some work experience as a foetus.'

He stared at me aghast. 'What can a foetus do?'

'Nothing,' I said. 'That's the point. You can be late enough into gestation to have ears and a brain, so that you can observe some of what's going on, but you aren't able to play any active role in the plot. For once, you need to listen and learn.'

For once, Miles played his part without deviating from the plot: being poisoned by the antidote to the soltoxin gas; being transferred to a uterine replicator for emergency medical treatment; being kidnapped and becoming the motive for an unauthorised commando raid that in passing led to the slaying of the villain and the end of the civil war; and, finally, being born, healthier than anyone had dared hope but still undersized, deformed and fragile, and being the reason for his parents, and one of his grandfather's armsmen, becoming estranged from his grandfather the Count.

I had expected Miles to resent not having any agency in the story. I hadn't expected him not to want to leave. When he reappeared in my office, back in his 17-year-old form, he looked disappointed.

'Any thoughts?' I asked.

'I was hoping to see how it turns out.'

'Really?'

'Yes. The people there: my mother, defying danger, prejudice, the chain of command, and even the risk of destroying her marriage, to rescue me in the middle of a war; the two guards with her, the traumatised war veteran and the young woman who is frustrated at not being allowed to be a real soldier and is just finding out how grim a war can be; my father, being so unshocked when his wife goes AWOL for days and comes home with a foetus in a replicator and a severed head in a shopping bag; even my grandfather who wants to kill me – they're all people I'd like to get to know. I just wish Princess Kareen hadn't got killed. She seemed a really interesting princess, not like Buttercup at all.'

'She is.' I bowed my head in sorrow for a character who should have had the chance to be the hero of her own story, and should have lived long enough to get a happy ending.

'Can I go back for an epilogue? When I'm, say, about five years old?'

'That's not as simple as it sounds,' I said. 'Appearing as a foetus, or even as a newborn, you don't actually have to do anything. But if you appear as a child, you're a character, and so you're signing up to be in this set of novels. Barrayar isn't an easy world for someone who looks like you…' No, danger and difficulty weren't going to deter Miles. 'I can't guarantee that many people will ever read you,' I warned him. 'Science fiction isn't necessarily mass market – at least, not when it's about cultural clashes and people struggling to overcome the prejudices of the lost colony planet they live on, rather than about a small band of rebels overthrowing Emperor Zhark.'

'What's the Emperor of Barrayar like?' Miles asked, and by now he looked a lot nearer five than seventeen.

'Very unlike Zhark. He's Princess Kareen's son. He's five years older than you. Your Mama and Da will be looking after him, now that his Mama is dead.'

'So he's my brother?' Miles beamed at the thought of having a brother, and then he vanished back into the epilogue of Barrayar, decision made.

[Epilogue: five novels later]

'I don't want to be Miles Vorkosigan!' protested the short, ugly teenager.

'Then don't be,' I said.

'What else am I supposed to do?' he snapped. 'Just because I got sent to a dormitory in the Vorkosigan universe – and it wasn't even on Barrayar, it was on Jackson's Whole – I started looking like this!'

He gestured up and down his short, crooked body. He really did look virtually identical to Miles: the same facial features, the same black hair and grey eyes, and even the same scars. The only difference was that he didn't seem quite as fragile as Miles. He was clearly ill-treated and underfed, but looked as though he might grow into quite a sturdy young man.

'You're still a Generic,' I said reassuringly. 'There's plenty of time to change the way you look before you graduate. It's one of the easiest things to change, compared with character traits. Do you think if you moved around between authors, it might help?'

'I've tried. It doesn't work. The only job I'll ever get now is playing a fanfiction version of Miles, and they'll probably force me to have sex with Gregor.' He sounded defiantly defeatist. I feared that 'looks like Miles Vorkosigan and hates it' had already become his defining character trait.

'You've got plenty of time yet,' I said again.

Unfortunately, I was wrong. Before he had been able to complete his training, decide what his motivation was or choose a name, he was kidnapped and forced into the plot of a novel under construction about a terrorist conspiracy to replace Miles with a clone who was a trained assassin.

I wanted to rescue my Generic. Miles, excited to have a real brother at last, wanted him to be a regular member of the cast of characters in all following books. The Generic himself had found a plotline of his own within the Vorkosigan universe that he wanted to pursue, as long as he didn't have to be in the same novels as Miles, or at least not in the same chapters, so that they didn't have to interact with each other. He still hadn't decided on a name, though he emphatically rejected Miles's suggestion.

I wanted to take him back to St Tabularasa's and give him time to complete his training and think through his options. But now that he had taken on the persona of a troubled young man who had been brainwashed and exploited for his entire life, he was unable to trust me, or to see any difference between Ser Galen and St Tabularasa's Training College for Generics – or Miles, for that matter. As far as he was concerned, anyone who wanted to take him under their wing was the enemy.

So he needed to complete his character development in-universe, by living and interacting with other characters. But then, I suppose that's how Outlanders do it, and it seems to work all right for them, going by the few Outlanders I've met. By the second novel he appeared in, this Generic had developed enough personality to share the responsibility of being POV character with Miles, and by the end, he had found a name and an identity – or, to be precise, five identities, only one of which answers to the name 'Mark'.

He's done well since then. I think he could handle being sole protagonist if he wanted, but he says he's too busy to do more than share the job, and besides, he wants to get some privacy with his girlfriend, which he can't have if they're constantly being read.

Yes, he has a girlfriend – and the next novel they are scheduled to appear in is planned to be a romantic comedy. I can't wait to see how that turns out. After all, it's about time someone challenges Heathcliff for the 'Most Troubled Romantic Lead (Male)' award at the Bookies – and if anyone can do it, Mark can.