He was awakened, he thought, by tapping on the window of his bedroom. Digory Kirke roused himself and stood by the casement. There was no moonlight or starlight; the clouds were unbroken. The unsleeping lights of the great city kept the sky from being black. Digory could see that the branches of the apple tree did not reach to within ten feet of the windows. What could it have been then, he asked. A squirrel, a rat? Preposterous. Perhaps he had been dreaming. He turned the handle and flung the window open. He was shocked by the blast of cold air. It had been a cold, dreary spring. That and the steady stream of unsettling news from the Continent had lowered his spirits. The apple tree in his yard was delayed in blooming, he thought, looking at the inky lines of its branches in the dark.

He found it convenient to keep a house in the city but he much preferred his cottage near the university and of course his country retreat with its park, stables and kennels, and the surrounding woods. He shut the window with a shudder. The house still had the power to remind him of the days when his mother lay on her sick bed and he despaired that she would live beyond his childhood. He would not have stayed overnight if he had not received a letter from an old friend asking to meet him here. Why had he been dreaming of the tree, he wondered. He did not often think of it these days. He put the thought out of his mind and returned to bed.

Under the overcast morning sky the figure of a woman stepped out of the black cab. She was in a blue wool coat with matching felt hat. She wore sensible shoes, Digory observed. He grinned with delight. He had not seen his childhood friend Polly in years, although they had corresponded more often. He hurried to the door.

Polly greeted him with a look of calm pleasure. Her grey eyes were lively as ever. She had changed only slowly with the years. Digory felt uncomfortably conscious of his growing waistline. He was beginning to look the image of the middle-aged professor who spent his hours behind a desk with no longer any time for the active life. "Well, do come in," he said cheerily.

At her side was a boy. This was her youngest, Stephen. Digory was not surprised to see her accompanied as she had mentioned it in her letter. The boy wore a duffel coat. His black Oxfords had been well shined. On orders from his mother no doubt. Digory thought his face looked soft. His skin was pasty without any underlying rosiness. There were dark circles under his eyes. Digory hoped that his concern was not too obvious. "Pleased to meet you, my young fellow," he said heartily, reaching out and shaking the boy's hand. The boy continued to look at him with placid steadiness.

"You know, Edward is stationed only an hour and a half from town by train. It's very convenient," said Polly when they were settled in the sitting room. "I could visit you more often, if you like."

"I would like that very much." As her family had been growing up Polly had had to uproot them to follow her husband, Captain Edward Sears, in his postings. Digory could appreciate her delight at being close to London again.

"I'm not at this house very often," Digory continued. "I suppose I should air it out a bit more. I've neglected it." Polly's eyes scanned the interior slowly. There was a trace of a smile on her lips. "Oh, there's nothing left of my uncle's," said Digory, "if that's what you're looking for." Digory's uncle Andrew had been a magician. It was he who had fashioned the magical rings that took them to other worlds so many years before.

Digory fetched the tea things and poured cups for the three of them. "You must try this lemon pudding cake." Polly smiled indulgently at the sight of Digory clumsily working the slices of cake on to plates. She knew he was not used to hosting company on his own. In his rooms at college the staff would have taken care of such chores. Digory hadn't changed much, she thought. Just look at his hair. Though now streaked with grey it was as heaped up and unruly as ever.

"The other children are doing well, I take it?"

"Very well," Polly said between sips of tea. "Michael is working at a firm of accountants. He hasn't decided whether he wants to take it up as a profession, but I do hope so. Elizabeth is assistant to an editor at a publishing company. She earns a living reading children's books, imagine that! It's wonderful the opportunities available to girls nowadays. And Evelyn is still in school, of course."

Digory nodded appreciatively. Even though he tended to be bored by domestic details he enjoyed the warmth of Polly's voice, her pride and affection.

Stephen was sitting on the chesterfield, saying very little. To Digory's disapproving gaze he seemed a trifle on the pudgy side. That was not a healthy sign in a boy. When Stephen had finished his tea and cake his mother said rather loudly, "Why don't you go buy some sweets for yourself? We saw that shop down the street." She snapped open her purse and handed her son some change.

"Yes, Mother," Stephen murmured and dutifully headed out the front door.

Polly turned her attention to Digory. "I'm being mysterious, aren't I?" Polly's eyes lit up. "You're dying to know why I've asked to see you here."

Digory felt a curious sensation. It was not that he was reminded of the appearance of the youthful Polly. In fact, he could not remember clearly what Polly looked like as a young girl. There were photographs taken of course but these he had carelessly stored away some place. No, it was less tangible than that. He felt as if a warm breeze from the past was blowing. He closed his eyes and took a deep breath.

Polly turned serious. "I'll get to the heart of the matter. My son Stephen has always been a sensitive child. He would cry from fear of things that he had imagined: strange noises, presences outside the windows or in the attic. No one could ever see the things that set him off. You no doubt think that I've indulged the boy excessively. Perhaps so.

"Lately he has told me he hasn't been sleeping well. He has dreams that disturb him. He can't or won't tell me the details. I've always encouraged him to express himself artistically. He's been drawing rather obsessively of late. Here are a few of his drawings."

Polly opened her purse again and unfolded sheets of paper. Digory could see that the child had exerted considerable pressure to make dark, flowing lines with a thick pencil. It was as if the child were possessed by a vision that he needed to release. At the same time the drawings were minutely detailed. All the drawings were variations on the same subject: a massive tree with apples hanging from its boughs. In one of the drawings a young woman was shown with her back pressed against the trunk. Or one might have said that she seemed to be emerging from the trunk. She was slender with long sinuous arms. Her hair cascaded down almost to her waist. In Digory's eyes there was no mistaking the subject. This was the Tree of Protection in far-off Narnia and its dryad.

"I know you wouldn't have forgotten this," Polly said. "Or her."

Author's note. I am thankful for all those who have written 'Fall of Narnia' stories, Magician's Nephew sequels and Polly andDigory stories although I'm sure I haven't paid as much attention to them as they deserve. In particular, a story by the awesomely productive Rosa Cotton was one inspiration.