The man on the tree trunk didn't wave back. Instead, he raised his hat slightly and angled it towards Lucy slightly, and then, with his other hand, raised his walking stick in front of him, like a sword. Lucy started to giggle, but stopped a few seconds later, when the man replaced his hat, lowered his stick and slowly raised himself into a standing position.

Oh no, she thought, he's coming over here. She took in a deep breath and then let it out slowly, trying to work out what she should do. After all, mum and dad and the teachers at school were always on about how kids should NEVER talk to strangers, and the man now moving towards the field gate across the lane was not only a stranger - he was quite a strange stranger, to judge from his funny-looking suit and hat.

She looked down and checked the padlock on the garden gate. It was there, as usual, and very much locked, looking big, brassy and solid, and the gate itself came up not that far below her chin, although Lucy realised that it wouldn't take an adult very long to climb over it.

Mind you, she thought, it would still take someone a few seconds to manage that, and she could run pretty fast, as only two of the biggest boys in Middle School had ever managed to beat her in a fair race. Besides, mum was upstairs, the window was open, and Lucy could manage quite a loud scream, if she had to.

All the same, as the man reached the lane itself, she stepped back a couple of paces, just to make sure he couldn't reach over the gate and grab her. Now she felt better, because in the time it took someone to get over the gate, she would already be a good way back up the garden path - and shouting her head off, she added to herself, smiling at the thought.

The man crossed the lane at the same leisurely pace and then, when he reached the pavement that ran along this side of it, raised his hat again, although he held his walking stick the way people usually held walking sticks and didn't give another salute with it.

"Good morning," he said, even before he reached the gate. "Very nice weather today, don't you think?" Lucy nodded, still not sure whether she should encourage him by speaking herself. He seemed pretty harmless, close up, probably about the same age as dad, but not the "21 again" he often claimed on his birthdays. No, more like the forty one that Lucy knew was his real age.

"Not at school today, then, young lady?" the man continued. For the first time Lucy noticed his moustache - it wasn't much of a moustache, more a collection of short bristles under his nose. She smiled at him, a sort of "don't you know anything?" smile.

"It's the school holidays," she replied. "We don't go back to school for another three weeks yet," she added, for want of something better to say. The man nodded.

"Ah yes," he said. "Yes, of course. I remember now."

"I should think so," Lucy said. "It can't be that many years since you went to school, can it?" The man gave a very brief chuckle, more like someone clearing their throat than a real laugh.

"Well, it depends what you mean by 'that many years', doesn't it?" he said. "And, when I was your age, we were lucky if we got to go to school. A lot of parents couldn't afford school for their children."

"You mean they had to pay for you to go to school?" Lucy couldn't keep the surprise from her voice. "The government pays for school, surely," she added. It wasn't a question, it was a statement of fact. "Parents work and pay taxes and stuff and the government uses the money to pay for schools, hospitals and other stuff."

"Not when I was your age, they didn't," the man retorted, shaking his head slightly. Lucy's eyes narrowed.

"They must have done," she said, firmly. "Even my grandparents didn't have to pay for school - and they're pretty old, much older than you are!" The man chuckled again, this time for several seconds, and shook his head once more.

"You seem pretty sure of yourself, I must say," he said, at last. "How do you know how old I am?" Lucy shrugged.

"I'm a pretty good guesser," she said. "You seem about the same age as my dad, though you could be a year or two older or younger, I suppose."

"Yes, a year or two ... you could say that." The man let out a short laugh, and Lucy looked at him curiously. He didn't seem particularly odd, apart from his slightly scruffy-looking suit - and the hat and walking stick, of course, but she knew enough at her age to know that what people seemed to look like didn't necessarily mean much at times.

"My mum's just a bit younger than dad," Lucy said, an idea striking her. "You might see her at any minute now." She turned and pointed up towards the open window. "She's just up there, stripping wallpaper in the spare room, but she'll probably want a bit of a break at any minute now."

She turned back to face the man, feeling better now that she had made him aware that her mum was so close by, but nothing about his attitude appeared to have changed as a result of this news. Quite the reverse, in fact.

"You mum is Sarah-Jane, isn't she?" the man said, quite unexpectedly. "Used to be Sarah-Jane Martin, before she married your dad." Lucy's eyes widened in surprise.

"How did you know that?" she demanded. "Did you used to know my mum?" Again he laughed briefly.

"Well, not exactly," he said. "I know of her, and I know of your gran, her mum."

"Nanny Sue? How do you know about her, then?" A little voice was trying to tell Lucy that she really ought to end this conversation, make an excuse, maybe, and go back up to the house. This man could be almost anybody and just because he knew her mum's name didn't mean anything - and now she'd gone and given him her nan's name as well, so he could pretend anything.

"Susan Lewis, she used to be, aye," he said. Lucy frowned. She couldn't be one hundred per cent absolutely and totally sure, but she had heard the name Lewis before, because she had a couple of nearly-cousins with that surname, but she wasn't quite sure how they were related. More importantly, this time she definitely hadn't given this man any sort of clue to the name.

He seemed to sense that she was puzzled - and beginning to worry a bit.

"I ought to explain, really," he said, his face suddenly becoming serious. "But I'm not quite sure how to start, because, quite honestly, when I tell you what I have to tell you, you're going to think either that I'm completely mad, or that I'm the biggest liar this side of a long way away."

"Oh yes?" said Lucy. She took half a step further back and studied him carefully for a few seconds. Then she remembered something she'd heard her dad say in the past. She nodded and put her hands on her hips, trying to make herself look taller.

"Why don't we let me be the judge of that?" she suggested. The man looked back at her, smiled and nodded.

"All right then," he said, "but don't say I didn't try to warn you." He scratched the side of his nose gently. "Because," he went on, "what I am about to tell you will seem like a very unlikely story - a very unlikely story indeed."