It is unusual for George's father to speak to him after prayers have been said and the light turned out. They are supposed to reflect upon the meaning of the words while yielding themselves to the bosom of God's sleep. In truth, George is more inclined to carry on thinking about the next day's lessons. He does not believe God will count this a sin.

'George,' his father suddenly says. 'Have you noticed anyone loitering near the Vicarage?'

'Today, Father?'

'No, not today. Generally. Recently.'

'No, Father. Why would anyone be loitering?'

'Your mother and I have been receiving anonymous letters.'

'From loiterers?'

'Yes. No. I want you to report anything suspicious to me, George. Somebody pushing something through the door. People standing around.'

'Who are these letters from, Father?'

'They are anonymous, George.' Even in the dark he can sense his father's impatience. 'Anonymous. From the Greek, then the Latin. Without a name.'

'What do they say, Father?'

'They say wicked things. About… everyone.'

George knows he is meant to be concerned, but finds it all too exciting. He has been given authority to play the detective, and does so as often as possible without interfering with his school work. He peers from behind the trunks of trees; he obscures himself in the cubbyhole beneath the stairs to watch the front door; he examines the behaviour of those who come to the house; he wonders how he might afford a magnifying glass and, perhaps, a telescope. He discovers nothing.

Nor does he know who starts chalking up sinful words about his parents on Mr Harriman's barn and Mr Aram 's outbuildings. As soon as they are washed off, the words mysteriously reappear. George is not told what they say. One afternoon, taking a circuitous route like all the best detectives, he creeps up on Mr Harriman's barn, but all he espies is a wall with some wet patches drying.

'Father,' George whispers after the light has been put out. He assumes this is the permitted time to talk about such matters. 'I have an idea. Mr Bostock.'

'What about Mr Bostock?'

'He has lots of chalk. He always had lots of chalk.'

'That is true, George. But I think we may safely eliminate Mr Bostock.'

A few days later George's mother sprains her wrist and wraps it in muslin. She asks Elizabeth Foster to write the butcher's list for her; but instead of sending the girl with it to Mr Greensill, she takes it to George's father. After comparison with the contents of a locked drawer, Elizabeth Foster is dismissed.

Later, Father has to go and explain things to the magistrates at Cannock. George secretly hopes he might also be asked to give evidence. Father reports that the wretched girl claimed it was all a foolish joke, and has been bound over to keep the peace.

Elizabeth Foster is not seen again in the district and a new maid soon arrives. George feels he could have done better at playing the detective. He also wishes he knew what was chalked on Mr Harriman's barn and Mr Aram 's outbuildings.

Irish by ancestry, Scottish by birth, instructed in the faith of Rome by Dutch Jesuits, Arthur became English. English history inspired him; English freedoms made him proud; English cricket made him patriotic. And the greatest epoch in English history – with many to choose from – was the fourteenth century: a time when the English archer commanded the field, and when both the French and Scottish kings were held prisoner in London.

But he also never forgot the tales heard while the porridge stick was raised. For Arthur the root of Englishness lay in the long-gone, long-remembered, long-invented world of chivalry. There was no knight more faithful than Sir Kaye, none so brave and amorous as Sir Lancelot, none so virtuous as Sir Galahad. There was no pair of lovers truer than Tristan and Iseult, no wife fairer and more faithless than Guinevere. And of course there was no braver or more noble king than Arthur.

The Christian virtues could be practised by everyone, from the humble to the high-born. But chivalry was the prerogative of the powerful. The knight protected his lady; the strong aided the weak; honour was a living thing for which you should be prepared to die. Sadly, the number of grails and quests available to a newly qualified doctor was fairly limited. In this modern world of Birmingham factories and billycock hats the notion of chivalry often seemed to have declined into one of mere sportsmanship. But Arthur practised the code wherever possible. He was a man of his word; he succoured the poor; he kept his guard against baser emotions; he treated women respectfully; he had long-term plans for the rescue and care of his mother. Given that the fourteenth century had regrettably ended, and that he was not William Douglas, Lord of Liddesdale, the Flower of Chivalry himself, this was the best Arthur could currently manage.

It was the rules of chivalry, and not the textbooks of physiology, which governed his first approaches to the fairer sex. He was handsome enough to attract women, and robustly flirtatious; once, he proudly informed the Mam that he was honourably in love with five women at the same time. It was different from being bosom friends with fellows at school, but at least some of the same rules applied. Thus, if you liked a girl, you gave her a nickname. Elmore Weldon, for instance: a pretty, sturdy thing with whom he flirted furiously for weeks. He called her Elmo, after St Elmo's Fire, that miraculous light seen about the masts and yardarms of ships during a storm. He liked to picture himself as a mariner in peril on the seas of life, while she illuminated the dark skies for him. Indeed, he almost became engaged to Elmo; but then, after a while, he didn't.

He was also much concerned at this time about nocturnal emissions, which had featured little in the Morte d'Arthur. Damp morning sheets rather detracted from chivalric dreams; also from a sense of what a man was, or might be, if he put his mind and strength to it. Arthur sought to impose discipline upon his sleeping self by increased physical activity. Already he boxed, and played cricket and football. Now he also took up golf. Where lesser men consulted filth, he read Wisden.

He began to submit stories to the magazines. Once again he was the boy standing on the school desk, deploying his vocal tricks; the cynosure of raised eyes, the cause of mouths dropped open in credulity. He wrote the sort of tales he enjoyed reading – this seemed to him the most sensible approach to the writing game. He set his adventures in distant lands, where buried treasure could often be found, and the local population was high on black-hearted villains and rescuable maidens. Only a certain kind of hero was fitted to take part in the hazardous missions he sketched. For a start, those whose constitutions were enfeebled, those given to self-pity and to alcohol, were manifestly unsuitable. Arthur's father had failed in his chivalric duty to the Mam; now the task had devolved upon his son. He could not rescue her by fourteenth-century methods, so would have to apply those available in a lesser age. He would write stories: he would rescue her by describing the fictional rescue of others. These descriptions would bring him money, and money would do the rest.