The Doctor could see the heat rising from it as she held it tight in her hands, close under her chin. Occasionally she sneaked furtive sips from the hot liquid.

The children ran past and round her, without comment or worry. It was interesting, the Doctor thought, the patterns they made with their games. There was a symmetry to it. As though each was following the other, taking his or her cue from another child who in turn...and so on. Snakes eating their own tails, he thought ruefully.

The teacher caught his eye and smiled. No problem with strangers, the Doctor decided. She probably already knew exactly who he was - or rather, who he said he was. Probably the rest of the children did too. Not one had glanced across at him, remarked him, noticed his clothing. He was a bit disappointed, actually.

And partly because of this, he pushed the gate open and strode across the playground towards the teacher. The main part of the playground was compacted earth. There was a gra.s.sed area off to the side that stretched round behind the school building. It looked like it opened out and became a playing field further round - the Doctor could see goal posts.

The children continued their game, running past and round him like shallow water flowing over a stone. He smiled and nodded at them. They grinned and laughed back. And for a few paces life was wonderful.

The teacher released her shivering grip on the mug with one hand for long enough to shake the Doctor's hand. It was coffee, he could smell it now.

'Miss Devlin,' she said. She had a cold. 'You must be the Doctor.'

'Ah, you've heard of me.' The Doctor beamed hugely.

'News travels fast.'

She nodded, her eyes on the racing children as they screamed by. She was quite short, wrapped in a huge coat, mousy-brown hair wisping out from beneath a headscarf. She had a collection of bangles on her left wrist and they jangled as she moved her hand. Or shivered.

'Are you their teacher?' the Doctor asked. 'Their only teacher?'

'With so few of them, it's easy enough despite the age difference. Better a cla.s.s of eleven happy enthusiastic youngsters than thirty or more little devils all refusing to learn the same thing.'

The Doctor nodded. 'I suppose so. And are they?'

'Little devils?'

'Enthusiastic.'

'Oh yes.' She smiled thinly, to show it had actually been a joke. He smiled back to show that he knew.

'I've been watching them,' the Doctor said. 'So much energy to burn off.'

'You're telling me. They're worse when it's windy.

Quieter in the fog.' She shrugged towards her coffee. 'Funny how the weather affects them.'

They watched the children for a while. They were playing a form of tig. For a moment they were all still, frozen in place as the game paused. Then, 'Budge,' shouted one boy. And they were off again.

'I've been watching the patterns they make. When they run.'

She nodded. 'I noticed that too. Just these last few weeks.

Perhaps since the weather turned colder.' She sipped at the drink again, barely letting it touch her pale lips as she slurped at it. 'They've been playing better together recently. All ages, all mucking in. The older ones used to stand around, talk.' She made to drink some more, but paused before the mug was even close to her mouth. 'It's time I called them in for lunch, if I can calm them down a bit.'

'Already?'

'It's cold.'

'It is,' the Doctor agreed. 'I like children,' he said wistfully. A sudden thought occurred to him. 'Mind if I show them something? A trick. To calm them down.'

She shrugged again. He took this as a 'yes' and strode out into the middle of the playground. The children seemed to sense that he was here for their benefit and crowded round him. He rummaged in his pockets, wondering now he was committed what he was actually going to do. Yo-yo? Sweets?

Ah - cards.

The children watched, respectfully and surprisingly quietly as he pulled the deck of cards from his pocket and shuffled them.

'Show us a trick,' a girl called. She was maybe ten, with large front teeth and a ponytail of dark brown hair.

'Yes, a trick,' others chorused.

'All right, I'll show you a trick. Choose a card.'

'Ace of hearts,' a boy shouted immediately from the back.

'I meant from the pack,' the Doctor said. 'But all right.'

He cut the cards with one hand and flipped the top half over to reveal the ace of hearts. There was a smattering of applause.

He gave it a moment, then shuffled the cards. He made a play of riffling them together, slotting them into place, cutting them. 'Now,' he asked, 'where's the ace of hearts got to?'

'In the middle,' someone called.

'In your pocket,' an older boy said with determination.

The Doctor smiled. He held out the pack, face down.

'What's the top card?' he asked the ponytail girl.

She lifted it carefully. 'It's the ace of hearts.'

More applause.

'Show me how to do it?' the girl asked nervously.

'It's a trick.'

'Oh, please!'

'All right. What's your name?'

'Emma.'

'All right, Emma.' The Doctor looked round seriously at the other ten children. 'n.o.body else watch. All turn away now, or it won't be a trick, will it?'

They grumbled and shuffled, and eventually turned away.

He was a good teacher. It did not take long. He showed her silently how to cut the ace to the top. He demonstrated how to riffle the cards and leave it untouched, how to shuffle them without disturbing its position. He let her try it on him once.

Then he winked and grinned and clapped his hands loudly together. 'Right, everyone. Emma has a trick. Last one before lunch.'

At the back of the small group Miss Devlin smiled appreciatively.

Then Emma took centre stage. She showed them the ace of hearts, all serious, face a mask of concentration. She put it in the middle of the pack, and shuffled the cards. The tip of her tongue edged out of the side of her mouth as she worked. Then it disappeared as she gritted her teeth and held out the pack to the nearest boy. 'Josh,' she whispered.

He knew what to do. He lifted the top card. And he grinned, one tooth prominently missing as he showed the others. The ace of hearts.

Applause. Then, 'My turn - my turn.'

'I think it's time for lunch,' Miss Devlin said.

'Oh, please.' A cute six-year-old grabbed the cards. 'Let me, let me.' He showed the ace of hearts. The Doctor and Miss Devlin exchanged amused glances as he slotted it into the pack and shuffled clumsily. He held the pack out to the Doctor who smiled and lifted the top card.

It was the ace of hearts. He felt his own hearts miss a beat.

'That was kind,' the teacher whispered to him as he showed the card.

'Not really,' he muttered back. 'Do that again,' he told the child.

'James,' the boy said.

'Well done, James,' the Doctor said. 'Do it again.'

He did it again.

The Doctor took the cards. He checked them to see that they weren't all the ace of hearts. Well, you never knew. He allowed an older boy to lift the cards from him. And he watched the older boy do the same trick. Perfectly.

'You've done this before,' the Doctor said, realising. He watched as yet another child managed effortlessly to shuffle the ace to the top of the pack.

'No. Never,' they told him. And from their evident delight and glee he could believe it. Though he didn't want to.

Miss Devlin clapped her hands together. 'Lunch,' she announced. 'Now.'

Disappointed, but resigned, the children filed into the school. One of them handed the cards to Miss Devlin at the door. She paused a moment as the children shuffled past, waited for the Doctor.

'How very peculiar,' the Doctor said as the last child went quietly indoors.

'They pick things up very quickly,' she said. 'I was telling Dr Madsen the other week when he gave them their flu jabs.

After...you know.'

The Doctor nodded. He was aware of the impact of a death in such a small community, especially from something as apparently minor as influenza.

'They've got even quicker since then, if anything.' She was shuffling the cards herself now, a nervous gesture. 'The jab worked, though. I always get the flu.' The Doctor wondered where she had put the coffee mug. He would have looked round for it, but his eyes were fixed on her hands as they shuffled the cards. 'But just a slight cold this year.

Marvellous what they can achieve these days, isn't it?' She was not aware of what she was doing, wasn't even watching herself as she riffled the cards together again. 'It was kind of you to show them the trick,' she said. 'Thank you.'

'Not at all. I must let you get on.'

She smiled gratefully and handed him the cards. 'They're trick cards, aren't they? That's it, isn't it?'

He smiled, but did not answer. Perhaps it was better she should think that.

'You must come again,' she went on. 'Talk to the children.

Sir Edward was kind enough to come and talk to them the other week. They have so little contact with the real world.'

The Doctor smiled back. 'I'd like that,' he said. 'I know the problem.'

He waited until she had gone inside, until the door was closed firmly behind her, against the cold. Then he turned the top card over. And he felt the chill himself.

It was the ace of hearts.

Chapter Six.

Digging for Clues Peri was waiting for the Doctor outside the pub when he got there. He could tell that she was distracted, nervous. He did not ask what was wrong - better to wait until she was ready to talk about it. That would also give him time to decide what he would tell her about his experiences at the school.

He led her into the pub and they each got a gla.s.s of water and ordered a ploughman's. 'At least we know the bread will be home-baked,' he told her with a grin.

He waited until they were seated at what was becoming their 'usual table' before asking about her morning. He listened in silence, letting her go at her own pace. She started with an account of her run-in with Mike Neville.

'That's the trouble with strangers,' the Doctor said when she was done. 'They disrupt the normal processes, upset things. Things like procedures, processes. Emotions.'

'Hey, who gets the sympathy here?' Peri wanted to know.

'The man from the woods?' the Doctor suggested. 'I wonder who he is.'

'Just some nutter.' Peri shook her head and attacked a hunk of mature Cheddar cheese. 'He's weird. And talking of weird, you should see the sheep.'

The Doctor paused in the process of pulling apart his bread roll. 'Sheep?' he asked.

'That is strange,' the Doctor agreed when Peri had finished her story. He pushed his plate away, empty. Peri had barely started on hers. She had been doing all the talking. But she seemed calmer now, more herself. Time for the Doctor to do the talking. 'And talking of strange behaviour,' he said, 'I wonder if it's connected to the children.'

'The children?'