'What's the matter, Ian?'

'Feel it.'

Hesitantly, Barbara put her hand to the police box door. She, too, pulled it hurriedly back. 'There's a kind of faint vibration.'

Ian nodded. 'It feels - alive...' He walked all the way round the police box, reappearing at the front. 'Well, it's not connected to anything - unless it's through the floor.'

Barbara backed away. For some reason the police box made her feel uneasy. 'Look, I've had enough of this. Let's go and find a policeman, tell him we think Susan's missing. They can organise a proper search.'

'All right.' Ian paused as he heard the gate creak open. There was the sound of coughing. 'Someone's there!'

'Is it Susan?'

Ian could just make out a cloaked figure advancing through the gloom. 'No, it isn't. Quick, behind here.' He dragged her behind a pile of old furniture, and they ducked down out of sight.

The dark shape came nearer, and revealed itself as a white-haired old man wrapped in some kind of cloak. He wore an oddly shaped fur hat, and a long striped scarf was wound around his neck.

The old man paused for a moment, coughing as old people do, and patted himself on the chest. He seemed to be muttering... He went up to the police box, fished a key from out of his pocket and opened the door.

To the astonishment of the two watchers, a girl's voice came from inside the police box. 'There you are, grandfather!'

'It's Susan!'

'Ssh!' said Ian warningly, but it was too late. The old man had heard them. He slammed the door of the police box and whirled around.

Deciding he might as well make the best of it, Ian rose to his feet. 'Excuse me.'

The old man looked at him in mild surprise. 'What are you doing here?'

'We're looking for a girl...'

'We?'

Barbara, too, emerged from her hiding place. 'Good evening.'

The old man studied them for a moment. His face was old and lined, yet somehow alert and vital at the same time. His eyes seemed to blaze with a fierce intelligence, and a commanding beak of a nose gave his features an arrogant, aristocratic air. 'What do you want?'

'We're looking for one of our pupils,' said Ian rather lamely. 'A girl called Susan Foreman. She came into this yard.'

'Really? In here? Are you sure?' There was a sort of condescending scepticism in the old man's voice, like that of someone talking to an imaginative child.

'Yes, we're sure,' said Barbara firmly. 'We saw her - from across the street.'

'One of their pupils,' muttered the old man to himself. 'Not the police, then.'

Ian was alarmed by the half-heard words. Why was the old man worried about the police? 'I beg your pardon?'

'Why were you spying on her? Who are you?'

Ian realised he was being put on the defensive. Somehow it was as if he was the one who had to explain his actions.

'We heard a young girl's voice call out to you -'

'Your hearing must be very acute. I didn't hear anything.'

Barbara pointed to the police box. 'Well, we did. And it came from in there.'

'You imagined it.'

Barbara could feel herself getting angry. 'I most certainly did not imagine it!'

As if deciding Barbara was beyond reason, the old man turned to Ian. 'Now I ask you, young man,' he said smoothly, 'is it reasonable to suppose that anyone would be inside a cupboard like that?'

Ian's tone was equally calm. 'Would it therefore be unreasonable to ask you to let us have a look inside?'

The old man seemed astonished at the suggestion. He picked up an old painting, and studied it absorbedly. 'I wonder why I've never seen that before. Now, isn't that strange? It's very damp and dirty.'

'Won't you help us?' pleaded Barbara. 'We're two of her teachers - she's at Coal Hill School. We saw her come in and we haven't seen her leave. Naturally, we're very worried.'

The old man was still peering at the painting. 'It really ought to be cleaned...' He looked up at Barbara. 'Oh, I'm afraid all this is none of my business. I suggest you leave.'

'Not until we're satisfied that Susan isn't here,' said Ian angrily.

'Frankly, I just don't understand your attitude.'

'Indeed? Well, your own leaves a lot to be desired, young man.'

' Will you open that door? '

The old man turned away dismissively. 'There's nothing in there.'

'Then why are you afraid to show us?'

'Afraid!' said the old man scornfully. 'Oh - go away!' He spoke like someone dismissing a child whose antics have finally become tiresome.

'Come on, Barbara, I think we'd better go and fetch a policeman.'

Barbara nodded, watching the old man to see the effect of the threat.

He shrugged. 'Very well. Do as you please.'

'And you're coming with us,' said Ian in exasperation.

The old man smiled. 'Oh, am I? I don't think so, young man.

Oh no, I don't think so.'

He sat down on a broken-backed chair and picked up the painting again, studying it thoughtfully.

Stalemate.

Barbara looked helplessly at Ian. 'We can't force him.'

'We can't leave him here, either. Isn't it obvious? He's got her locked up in there.'

They moved closer to the police box. 'Try the door,' suggested Barbara. 'Maybe you can force it.'

Ian examined the lock. He thumped the door, but it was solidly locked. 'There's no proper handle - must be some kind of secret lock.'

'But that was Susan's voice - wasn't it?'

'Of course, it was.'

Ian rapped hard on the door with his knuckles. 'Susan! Susan, are you in there? It's Mr Chesterton and Miss Wright.'

Ian's banging on the police box seemed to annoy the strange old man. Abandoning his attempt to appear uninterested, he rose and came towards them. 'Aren't you being rather high-handed, young man? You thought you saw a young girl enter the yard. You imagine you heard her voice. You believe she might be hidden inside there?

It's not very substantial, is it?'

His words seemed to drain away Ian's confidence, leaving him wondering if he hadn't imagined the whole thing.

Barbara was not to be put off. 'But why won't you help us?'

'I'm not hindering you. If you're both determined to make fools of yourselves, I suggest you carry out your threat. Go and find a policeman.'

Ian said sceptically, 'While you nip off quietly in the other direction, I suppose?'

'There's no need to be insulting, young man,' said the old man loftily. 'There's only one way in and out of this yard. One of you can wait outside and watch the gates. I shall be here when you get back. I want to see your faces when you try to explain your behaviour to a policeman.'

'All right, that is what we'll do,' said Ian defiantly. 'Come on, Barbara, you can watch from the car, while I go and find a policeman.'

They were about to move away when the door to the police box was opened from the inside.

Susan's voice called, 'What are you doing out there, grandfather?'

The old man sprang towards the police box with tigerish speed.

'Close the door!' he shouted. He grabbed the door, obviously intending to slam it again, but Ian was too quick for him, and grabbed his arm, trying to pull him away. Despite his age, the old man was amazingly strong, and he almost succeeded in throwing Ian off. Barbara came and joined in, and somehow, struggling wildly, Ian and Barbara stumbled into the police box - and straight into sheer impossibility.

3

The TARDIS

Barbara Wright and Ian Chesterton stood gazing around them in disbelief, their brains refusing to take in the evidence of their eyes and ears.

They should have been inside an enclosed cupboard-sized space - but they were not. Instead, they stood inside a large, brightly lit control room. It was dominated by a many-sided central structure which seemed to consist of a number of instrument banks arranged round a transparent central column packed with complex machinery.