His thoughtful expression froze at George's answer.

'But don't you know?' George said. His voice was low, husky. 'It was Fitz.'

10: Fire and Ice

'What is it?' George asked. 'What's wrong?'

'I just realised,' Fitz said slowly. He stood up, stamping the life back into his feet and legs. 'I should have known all along of course, but I was more concerned that everyone thought it was me.'

'Sorry?'

'Thought it was me who killed Galloway.'

There was a distant scrabbling from the top of the sloping pa.s.sage, and a flurry of snow fell down into the cavern. It hung in the air like smoke.

'Yes,' George said slowly. 'I'm sorry about that.' He folded the paper he was working on and put it and the pencil in his coat pocket.

'Sorry about the suspicion falling on me? Or about murdering Galloway?' Fitz asked levelly. He could feel his whole body trembling with emotion. The cold wasn't helping.

Lumps of ice were sliding down the pa.s.sage into the cavern now. The scrabbling and sc.r.a.ping had intensified and almost without realising they were shouting at each other to be heard.

'About involving you, of course,' George was making his way across the cave towards Fitz. He jumped clear of a slew of ice and snow that slid out of the opening and across the floor. 'It was an accident, you know.' He sounded almost apologetic, but his eyes were fixed keenly on Fitz, waiting for his reaction.

'An accident? You hammered a b.l.o.o.d.y great tent peg through his head!' They were almost within reach of each other, but Fitz was yelling at the top of his voice, trying to be heard above the avalanche from the pa.s.sageway. 'How can that be an accident?'

And with the snow and ice and spray came the first of the creatures. It was sliding on its belly, legs splayed out and head twisting as it tried to catch their scent. Its roar shook the cavern and brought down chunks of ice from the ceiling high above which crashed around Fitz and George as they stood face to face.

'Perhaps we should defer our discussion until a more appropriate moment,' George shouted.

They were circling each other warily, unsure. An accident was possible, somehow? Could Galloway have fallen on the peg, maybe? Fitz wanted to believe, so much wanted to believe. He searched his friend's face for some clue. But George's expression was inscrutable, his eyes wide with adrenalin. Then George was suddenly reaching out for him both hands in a rush. Fitz stepped back, tried to duck away, but the hands connected with his chest and pushed, shoved, hurl him across the cavern.

Fitz sprawled on his back, desperately trying to drag himself away. And even as he did so, he saw the terrible lizard*creature's jaw snap down savagely on the empty s.p.a.ce where he had been standing. George was hurling himself after Fitz, tumbling across the icy floor to land beside him.

'I think this is it, you know,' George shouted above the creature's screech of triumph. It thumped across the floor towards them, the ice cracking beneath its feet. Behind it another of the beasts hurtled into the cavern. And another.

'Yes,' Fitz said. He doubted George could hear him. 'I think you're right. This is the time and the place. Let's put another scratch on the tablets of history.'

The grenade was warm in his hand, even through the glove. Time seemed to slow as he held it out in front of him; as he reached out his other hand and grasped the metal pin; as he pulled. As it came free.

The creature before them paused, its head slightly to one side as if puzzled, watching. George was yelling at Fitz, mouth working, but no sound. No sound at all. Underwater pressure in his ears as Fitz lobbed the grenade.

But not at the creature.

At the wall of ice where the tiny flames flickered, where the impossible fires were frozen.

The grenade twisted in the air, then skidded and bounced until it rested at the foot of the huge gla.s.sy wall.

The first explosion was almost a disappointment. An orange flare reflecting off the ice and percussing round the chamber. A billow of dark smoke. The creatures flinching, backing away. As the smoke cleared, Fitz could see that the whole wall of ice was glowing the flames inside erupting outwards, racing towards him as they broke free of the ice and threw its shattered remains across the cavern.

He pushed George, with all his might, hoped he would reach the shelter of a huge chunk of ice that had fallen from the ceiling.

Not waiting to see what happened to George, Fitz turned and dived across the cavern towards the ice*TARDIS. He twisted as he fell against it, against the cold doors. Saw George looking upwards from the ground, fear frozen in place as a tidal wave of snow and slush crashed down on him, burying him.

Then the doors split open under his weight, showering him with pinp.r.i.c.k splinters and shards, and he felt himself falling into the flickering interior of the ice itself. The creatures were silhouettes against the expanding explosion. The blast was white hot, intensely bright.

And the whiteness closed over Fitz, blotting out his vision, his hearing, his senses and stopping his heart in mid*beat.

The explosion lit up the evening sky, a huge beam of cold light cutting through the air and strobing upwards. The reality*shattering sound of the blast was heard as far away as Moscow.

9: Other Worlds

There was silence for several moments when George finished his story.

'Fascinating,' the Doctor said after a while. A gust of icy white steam accompanied the word. 'And you say that the TARDIS, the ice version of my blue box was positioned exactly where the real one is now?'

George nodded. 'But how can that be?' he asked.

'Does it matter?' Thorpe wondered. He gave the impression of being bored with the whole story.

'Well it might or it might not,' the Doctor said. 'Just as the ice*TARDIS that George here told us about is an image of where the TARDIS might or might not have one day been placed. Depending on decisions we made along the way.'

'Doctor,' Anji said, interrupting his enthusiastic flow. Her mind was numb with cold and shock, she was in no mood for one of the Doctor's rambling explanations.

'What is it?' He could see she was upset. As soon as he spoke, his own face fell. 'I'm sorry, Anji.'

'Fitz is dead,' she said. The words sounded flat, impersonal and devoid of emotion. Just as she felt drained and numb inside. 'He died in here.'

'I know.' The Doctor put a hand on her shoulder. 'I feel it too. But I already knew. I've had a while to come to terms with it. Since we were in Spain. Though I think I knew even before that, before I even met Fitz.'

'So what do we do?' The Grand d.u.c.h.ess was shivering. There was a mist of exhalation in the air in front of her.

The Doctor squeezed Anji's shoulder, then turned to the d.u.c.h.ess. 'I suggest we take a look and see if George's ice*TARDIS has turned up again now that reality has solidified round our decisions, as it were.'

'If I understood you earlier,' George said, 'what I saw was a possible future, is that right?'

The Doctor nodded. 'In simplistic terms.'

'Let's keep to those, shall we?' Anji said. She wiped at her eyes with her sleeve and felt the ice crystals sc.r.a.pe at her skin.

'So now the event has occurred, now your box really has been here, why would the ice*TARDIS, as you call it, reappear?'

The Doctor raised an index finger. 'Good point,' he admitted. 'Yes, very good.' He walked round in a slow circle as he considered this. 'I'll tell you what,' he said at last. 'We'll toss for it.'

Thorpe gave a short laugh. 'That's the scientific mind for you.'

'We'll what?' the d.u.c.h.ess asked in surprise.

'Toss a coin,' the Doctor said. 'I must have one somewhere. Heads we move the TARDIS and see what gets left behind. Tails we don't.'

'And that helps us precisely how?' Anji asked.

'It means we've not made a decision. It means we are leaving it to chance. It means there are two possible outcomes and that the TARDIS of five minutes from now is in an indeterminate state. It may or may not have been moved.'

'But the world doesn't work like that,' Anji told him. 'Or if it does, and the universe splits with every possible decision anyone makes, we don't notice it. Do we?'

'Not usually,' the Doctor said. 'Which is why I hope I really hope that if we move the TARDIS there will be nothing to see. Otherwise...' His voice tailed off.

'Otherwise?' George prompted.

'We're in trouble,' the Doctor said quietly 'No "ifs" or "buts" or "indeterminates". Real Real trouble.' trouble.'

The coin seemed to hang in the air caught at the very top of its spin, frozen in time. Then it fell, was s.n.a.t.c.hed from the air by the Doctor's fist and slapped down on the back of his other hand. He peeped carefully beneath his palm, angling so he could catch the light reflecting off the icy walls.

Then the Doctor grinned and pocketed the coin. 'Heads,' he announced.

'How do we know you are not lying?' the d.u.c.h.ess asked quietly.

'Trust you to think of that one,' Anji muttered.

'You don't,' the Doctor said. 'But that is at least half the point, isn't it?'

'The other half of the point being, how do we move this box of yours anyway?' Thorpe said.

'Ah, well, I'll just pop inside for a moment and I think you'll find that it moves itself.'

Anji frowned. 'Why didn't you get it here like that in the first place? If you know what I mean.'

'And let Hartford know just that tiny fraction of what the TARDIS can do?' The Doctor clicked his tongue in mock reproach. 'Think of the decisions he'd have made based on that.'

'But Thorpe will tell him anyway.'

'That was then, this is now,' the Doctor said. 'Circ.u.mstances have changed. We have less to lose. At least relative to Hartford's involvement. Sorry,' he added to Thorpe.

Thorpe shrugged. 'I doubt the Colonel will worry if your box turn out to be on wheels. Or skis.' He smiled thinly.

The Doctor shivered. 'Nothing quite so mundane. It's cold in here isn't it?', 'It is,' the d.u.c.h.ess told him emphatically. 'Can we leave now?'

'Give me just a moment.' So saying, the Doctor let himself into the TARDIS and the door closed behind him.

'I suggest we give him exactly five minutes,' Anji said. 'I've got a friend...' she blinked. 'Had a friend,' she corrected herself with a glance at George's shimmering form beside her, 'that the Doctor kept waiting for over a century.' a friend,' she corrected herself with a glance at George's shimmering form beside her, 'that the Doctor kept waiting for over a century.'

She was saved from having to explain this by the unholy mechanical sc.r.a.ping and trumpeting that was now coming from the TARDIS.

'What the h.e.l.l?' Thorpe's gun came up.

Jonas actually fired a shot, his face contorted with a mixture of surprise and fear.

The bullet ricocheted off the ice. The ice where the TARDIS had been.

The ice that was sculpted into exactly the same shape.

It was as if the blue box had lowly drained of colour, leaving behind just a translucent sh.e.l.l made of ice or gla.s.s. Anji took a step forward. The d.u.c.h.ess was holding her withered hand over her mouth in utter astonishment. The sound died away, leaving only the ice*TARDIS behind.

'I told you I'd only Oh.'

The Doctor was behind them, impossibly back in the cavern, picking himself up from his sliding reappearance down the slope. 'Must have slipped back a few seconds as well as over and up a few yards,' he murmured.

'I take it this is... not good,' Anji said, indicating the icy form in front of them.

'You could say that.' The Doctor was leaning over her shoulder, pointing along her line of sight. 'You see, deep inside?'

She did. Like the tiny flames frozen within the wall of the cavern, there was a burning heart to the TARDIS. A ma.s.s of orange and red flames unmoving within the ice. Trapped, frozen, still.

'I suppose there is a certain logic,' the Doctor said.

'There's no logic at all,' Thorpe said. Anji was pleased to see that he looked worried.

'After all,' the Doctor went on as if no one had spoken, 'the TARDIS is itself made of fire. In a sense.'

'What happened to you?' George was asking. 'And to the other box, the blue box?'

'Oh, it's back up on the sled,' the Doctor said matter*of*factly. 'Which is where we should be. It's time to go.'

'Somewhere where the fire is actually warm?' the d.u.c.h.ess asked.

'Oh that fire is hot enough, believe me. Release the potential exothermic energy trapped inside and you'd know about it.' A shadow pa.s.sed over the Doctor's face. 'A veritable volcano. But let s find somewhere more comfortably warm.'

'Good,' said Anji.

'There's just one little thing I want to do on the way.'

'Oh,' said Anji.