There was a sudden, short, sharp noise, and Zoe flinched, expecting a hail of bullets from the firing-squad.

But it was only the noise of the robot army stamping to attention. They did a smart about-turn, and then marched off into the darkness, leaving the three travellers alone in the middle of the empty plain.

'That must have been what they wanted the pa.s.sword... ' Jamie breathed a sigh of relief.

'I think so... "Begin at the Beginning" that's how all the best stories begin "Once Upon A Time",' agreed the Doctor. 'We've stumbled across the pa.s.sword the pa.s.sword to a world of fiction, where dreams and stories all come true.'

'But if we've got the pa.s.sword that means we're safe, doesn't it?' asked Zoe. 'It means we're free to go ' She broke off, listening. 'What was that noise?'

It was a drumming: a kind of throbbing that grew louder and louder.

Jamie looked about him, uneasily, and said: 'I have an idea I've heard it before somewhere... In fact I've got a funny feeling I've been here before... But I couldn't have could I?'

The Doctor put a hand on his shoulder. 'Ssh! listen... It sounds like a horse galloping.'

Zoe chimed in: 'It's getting nearer it's coming this way... Look there it is a white horse!'

Jamie followed the line of her outstretched hand: and then he stood transfixed, his face turning deathly pale. 'It's no horse,' he said huskily. 'D'you no see its one white horn as sharp as a dagger?'

'A unicorn!' gasped Zoe.

'My dream... ' whispered Jamie. 'Like you said my dream's come true... '

Zoe pulled at his arm: 'Quick run for it while we've still got a chance!'

'We have no chance at all,' said Jamie, as if he were under a spell. 'It's my nightmare again only this time I can't wake up.'

The unicorn galloped straight towards them, and the noise of its hoofbeats was deafening as it lowered its head, and charged ready for the kill.

5.

Into the Labyrinth The milk-white unicorn was a vision of beauty: moving with easy, liquid grace, its powerful muscles rippling under a satin skin. In the centre of its forehead, the single horn of polished ivory gleamed with a l.u.s.trous glow...

And it was pointing straight at Jamie's heart.

Beauty and terror combined to root him to the spot: he was powerless to run away. Zoe screamed at him to save himself, and tried to drag him bodily out of the path of the galloping animal: 'Run get away there's still time!'

But Jamie refused to budge, only shaking his head and saying: 'No... There's no time at all... I haven't got a chance.'

He never took his eyes off the unicorn as it raced nearer and nearer; he seemed to be almost hypnotised by it. He continued in the same flat monotone: 'Don't you see? It's my dream all over again.'

Zoe shook him desperately: 'It's not not a dream! It's real!' a dream! It's real!'

And then the Doctor gave a great shout of anger that startled them both.

'No!' he thundered. 'It is not not real don't believe that for an instant don't be fooled into believing these tricks... real don't believe that for an instant don't be fooled into believing these tricks...

There is no such thing as a unicorn it's a legend, a mythical beast... You mustn't believe in a thing that doesn't exist... Repeat after me: it doesn't exist!'

Jamie and Zoe took a deep breath and uttered the words obediently: ' It doesn't exist! It doesn't exist! ' '

The unicorn was almost on top of them but at the sound of their voices it suddenly stopped in its tracks, and stood there, only a few feet away, completely motionless.

The Doctor walked up and touched it. 'As I thought... '

he said ruminatively. 'Some sort of stone white marble perhaps? Not a living creature at all; merely the statue of a unicorn... Another test, sent to try us.'

Jamie blinked; his heart was still pounding, and his throat was dry. 'But it was real,' he croaked. 'We all saw it.'

'It was terrifying,' Zoe agreed.

'We thought we saw it.' Patiently the Doctor tried to explain. 'He challenged us to believe in it. And if we had believed it would have killed us.'

'You say "he" challenged us,' Zoe pursued. 'You mean the Master?'

'So I imagine... He seems to be the one responsible for setting up all these conjuring tricks.'

Jamie wiped his forehead: it was clammy and ice-cold he had never felt so close to death. But all he could say was: 'I don't understand... I wish I did.'

The Doctor paced slowly round the statue of the unicorn, appraising it from all sides. 'This unicorn seemed to be real until we declared that it wasn't. Once we all realised it was just another illusion, we were safe.'

'But we believed in it, Jamie and me,' Zoe reminded him.

'That was the danger: your belief was so strong, it almost convinced me as well. I had to hang on to logic, telling myself I must not believe the evidence of my own eyes. It was a very ingenious trap.'

Jamie shuddered: 'What kind of a mind would dream up a weird thing like that?'

The Doctor shrugged: 'I don't know yet. But I suspect we shall soon find out. Whoever the Master is, he must be some kind of creative genius.'

(Safe at the centre of his spider's web of operations, in the heart of the Citadel, the Master watched a single monitor screen, and listened with gratification to the Doctor's tribute.

'Too kind, too kind,' he purred. 'And in all fairness I really must return the compliment! Our good friend the Doctor is obviously a man of supreme intelligence. He is learning the rules here with admirable speed... Go in a little closer I want to get a better look at him.'

The image on the monitor screen slowly increased in size, as the Doctor's face shifted into a close-up.) Zoe suppressed a cry of dismay, and tugged at the Doctor's sleeve. 'The soldiers!' she exclaimed. 'They're coming back.'

The Doctor looked round: straight into the ray of' light which emanated from the lens on the toy soldier's helmet.

'Only one soldier this time,' he remarked. 'I wonder why.'

Then he spoke out boldly: 'Whoever you are whatever you want I accept your challenge.'

(In the Citadel, the Master rubbed his hands with glee.

This was turning out even better than he had dared to hope. 'Splendid, splendid... I know now we were absolutely right to choose the Doctor... But there is no need to rush things. About turn withdraw and let the prisoners go free... For the time being.'

He was prolonging the suspense, quite deliberately: this battle of wits was so enjoyable, he wanted to keep it going as long as possible.

'After all,' he added, 'wherever they go, wherever they may try to hide, each step they take will only bring them nearer to us... The plot is hatched the trap is set... All we have to do is wait and let them walk into it... About turn!

Quick march!) Zoe and Jamie stayed close to the Doctor, and watched in amazement as the toy soldier stepped back, turned, and retreated in its usual left-right-left-right fashion the key between its shoulderblades slowly unwinding as it moved off into the darkness.

'I wonder what happens when the clockwork runs down?' mused the Doctor. 'Does the Master wind them up again?'

'Why have they left us alone?' Zoe asked. 'What's going to happen?'

'Let's not wait to find out,' said Jamie quickly. 'Let's get out of here as fast as possible... Come on!'

As Zoe pointed out, long afterwards: 'For three s.p.a.ce travellers, used to covering vast distances through unknown galaxies, at speeds far greater than light we seemed to spend an awful lot of time trudging along on our own flat feet in this adventure!'

Certainly, they did a great deal of walking: they left the black, empty plain behind them and struggled onwards without any clear idea of where they were going or why.

Some strange compulsion drove them on, and the Doctor tried to define what it was.

'Fear? No it can't be that: because we don't know where we're going, and the greatest fear of all is the unknown... I'd say that the motive that keeps us going is curiosity. We want to find out what is going to happen next it's as simple as that.'

As they walked, they talked: and Zoe remembered to tell her companions of the strange experience she had, just before she fell down that never-ending hole in the ground when she found that her silver jumpsuit had been replaced for a time by an old-fashioned blue dress, and a ribbon in her hair, and high-b.u.t.toned boots.

'You must have looked like Alice in Wonderland,' the Doctor realised.

They did not know what he was talking about for Jamie had been born long before Lewis Carroll wrote about Alice's adventures, and Zoe, whose education had never included cla.s.sics of literature, had not heard of the young lady either.

The Doctor tried to explain: 'Alice is a fictional character, just like the unicorn and, I suspect, our eighteenth-century friend in the three-cornered hat...

We're exploring a world of fiction and fable, where nothing is completely real.'

Jamie interrupted: 'You mean these woods we're coming to yon bushes and shrubbery they're not there at all?'

For by now they had reached a gra.s.sy upland, where the stony floor of the plain gave way to lush vegetation. Exotic wildflowers blossomed on all sides, and they soon had to push their way through a thick underbrush, with rich green leaves and overhanging creepers.

Zoe sniffed: 'It's warm and wet... like a tropical rain forest.'

The Doctor agreed: 'The setting for an adventure story set in a fantastic jungle, no doubt.'

Brightly-coloured birds macaws and parakeets fluttered through the trees with startlingly shrill voices and at one moment a huge plant with lurid fleshy petals, fringed with sticky hairs, snapped shut as they pa.s.sed it, making them all jump.

'An author's overheated imagination must have dreamed that up,' said the Doctor with mild disdain.

'Venus Flytraps don't ever grow to that size it was obviously meant to be a man-eating orchid!'

'I'm certainly glad it's not real,' said Jamie, with feeling.

'And I suppose this face I've got that isna my face at all that's not real either? Well, that's some comfort, I reckon.'

The further they went into the jungle, the more dense it became, and they had to force their way through thick screens of leaves, and 'Ugh!' cried Zoe, with disgust.

'Spider's webs!'

The filmy grey webs stuck to her fingers, and she wiped them on a large green leaf then shivered in dismay as a furry body with eight s.h.a.ggy legs scuttled away crossly, its hiding place disturbed.

'I don't like this place,' she said plaintively. 'Can't we get into another story soon?'

'Don't despair,' said the Doctor, peering through the riot of tropical vegetation. 'There seems to be some sort of building just ahead of us... A ruined Inca temple, possibly?'

But when they finally pressed through into a little clearing in the forest, and the building was revealed, they found out that the Doctor's guess was wrong.

'It's a different story altogether,' he concluded. 'In a different time and place an old-fashioned mystery novel, by the look of it.'

There was a splendid mansion, with a row of white pillars holding up the main portico, and long, louvred shutters to the windows on either side. But the house had seen better days: the stucco was crumbling and flaking away the shutters needed a coat of fresh paint, and some of them were hanging askew, half off their hinges. The building was set among thick trees and shrubs magnolia and rhododendron that were a riot of vivid blossom, and seemed to be encroaching upon the house as if they would swallow it up.

'I wonder who lived here,' the Doctor pondered aloud.

'Some strange, tortured heroine of romance, I'd imagine...

From the pen of a pa.s.sionate female novelist!'

'There's only one way to find out,' said Jamie, and he bounded up the three cracked steps that led to the front door. Taking the bra.s.s knocker in his hand, he gave it a loud thump, and waited for a moment, then called out: 'Is there anybody there?'

n.o.body came, and n.o.body answered. Only a bird flew up out of a turret above the traveller's head; and he smote upon the door a second time.

'Is there anybody there?' he said.

(The Doctor gave a little nod of recognition: he had read that poem by Walter de la Mare, once upon a time, long, long ago.) But the second summons had been more successful than the first: for this time there was the squeak of a rusty bolt being drawn, and the click of a lock turning and the front door swung open, protesting, upon its hinges.

Jamie recoiled in alarm but it was too late.

For there, inside the door, stood the same Redcoat soldier he had encountered when he first arrived in this confusing place with the same flintlock musket aimed at his head.

Jamie wasn't going to show he was afraid that was certain.

'So it's you again!' he shouted. 'Well, this time, I'll take care of you for sure! Creag an Tuire! Creag an Tuire! ' '

And with his war cry, he drew out his sheathknife to defend himself.

As before, the soldier fired the musket: there was a loud bang, and a cloud of white smoke... And when it cleared, the Redcoat had vanished, and in Jamie's place was a two-dimensional cut-out... A storybook ill.u.s.tration of a boy in a kilt but a boy without a face.

Zoe gave a cry of grief and terror: 'Oh, no Jamie Jamie oh, Doctor, what have they done to him?' oh, Doctor, what have they done to him?'