Then he was gone.

Mauvril looked at the bas-reliefs on the wall. She looked at the Tractites in agony, the blaze of power from human weapons.

Then she made her decision.

They found another part of the message further down the ravine. Sam spotted it first. It was engraved on a different kind of rock, inverted, and weirdly distorted, the letters almost unrecognisable as such: but, now they knew what they were looking for, it was easy enough to work out what it said. There were two pieces, separated by a fault line: ATED 1.07 MILLION YEARS BEFORE Y and

ED INTO THE VOLCANO JUST BEFOR.

'A million years before?' asked Jo. 'Before what?'

'Before now, I suppose. I reckon the TARDIS materialised in the volcano no, that can't be right, they'd never have got it out. On the slopes?'

A grunt from Axeman. 'There!'

He was pointing at the opposite wall of the ravine, at something that glinted in the sunlight.

More letters, smaller, made of patterned quartz set into the rock. Jo looked at Axeman, who was staring at the pattern with a curious expression on his face. He'd obviously realised what sort of shapes they were looking for. She wondered if the TARDIS had translated the words.

HE WILL FIND YOU. BEWARE ARMED.

TRACTITES. I AM IN THE MAIN D.

'Armed Tractites?' Sam seemed bewildered.

'I told you,' said Jo. 'They always turn out bad in the end. I'm more worried about who's going to find us.'

'There!' said Axeman again.

Sure enough, there were more letters, in the same quartz pattern: BASALT.

If only Rowenna were here, thought Jo. If only Rowenna were alive alive. She would know how to find more of the message.

It must all be about the same age, from whenever the Doctor got stranded. He must have carved it lots of times.

'I've got it,' said Sam suddenly. 'The TARDIS is here! That's what he's trying to tell us!'

Jo turned, stared into the younger woman's eyes. Sam was actually jumping up and down, her face flushed, running her hands through her hair in excitement.

'It has to be here!' she said. 'It's obvious! Otherwise we'd never have been able to understand Axeman! And "volcano"

and "basalt" he must have landed it in the middle of an eruption, the dozy idiot.'

' "Beware armed Tractites"?' asked Jo.

Sam stopped jumping up and down, looked down at her muddy and battered trainers. 'Umm.'

'I think he got himself captured. "I am in the main d"? Is that "dome"? "Dormitory"? "Destructor unit"? And there's probably any amount of volcanic basalt round here and no way of telling how old it is. Even assuming it isn't buried under a thousand feet of more recent sediments. We've got to find more of the message, something more specific.'

'And we'll have to find it quickly,' said Sam. Her voice was strangely thick.

Jo looked at her, saw that her face was still red. So it wasn't excitement. 'Are you ' she began.

Sam nodded. 'I've got a fever.'

CHAPTER 21.

The air was drier here, on the slopes of the volcano. The land fell away to the west, showing Kitig a wide variety of landscapes: scarps, soda lakes, green swathes of forest on the rainward flanks of the hills, drier grasslands on the flats, all of them fading away into the hot glow of the afternoon.

He raised the crude chisel he had made from metal scavenged around the settlement, and resumed his work, hammering at the hard basalt, copying the square, awkward lettering the Doctor had palmed to him in the cell, all those months ago. He didn't know what the message meant whatever translation system allowed him to talk to the Doctor didn't work for this script but it didn't matter. The Doctor's instructions had been explicit.

Carve the message as many times as you can. In letters as big as you can make them. In as many different places as you can.

Kitig meant to do just that.

He meant to keep carving the message for the rest of his life.

Sam was struggling to think, but her hands were shaking.

No, she thought. I am not not dying. I dying. I haven't haven't caught one of Jacob's viruses. It's just a tropical fever nothing serious I'll shake it off and we'll go and look for the TARDIS and everything will be fine. caught one of Jacob's viruses. It's just a tropical fever nothing serious I'll shake it off and we'll go and look for the TARDIS and everything will be fine.

The ravine had widened out, the walls sunk down, the half-dry river come to an end in a muddy water hole. Sam was in the shade of a solitary tree. Jo was looking under a rock overhang on the other side of the water hole, where Axeman, eager to please, had found some new words.

'L, then another L, then "find her", then an O,' Jo reported. 'It's no good Sam, we could go on for ever like this. The message could be quite complicated.'

I'll find her? thought Sam. find her? thought Sam. You'll You'll find her? The Doctor sometimes called the TARDIS 'old girl'. Maybe he'd just said find her? The Doctor sometimes called the TARDIS 'old girl'. Maybe he'd just said 'You'll find her' in an effort to reassure them. Or maybe O was the beginning of 'on', directing them to some specific place.

If only there were more time time.

Sam closed her eyes, felt her bones ache. She felt more ill than she had at any time since a bad dose of flu at fourteen.

Her thoughts were beginning to cloud up, get confused. If only she could get to some water not the tepid, muddy, infected-looking water in front of her, but the cool, clear water of the cave in the habiline's settlement A hand, shaking her shoulder. 'Sam? Does the TARDIS still look like a police box?'

Sam looked blearily at Jo, nodded. 'Circuit stuck, or something.' She struggled to raise a smile. 'Least, that's what he says.'

Jo smiled back. 'I've thought of something.'

Sam sat up, swallowed a thick gob of saliva. Her throat hurt.

Perhaps it was just flu, or malaria, or something.

Jo was drawing with a stick in the mud at the edge of the water hole. Axeman crouched nearby, water dripping from his chin where he'd been drinking. He watched.

'Words,' said Jo, pointing at part of the picture. 'Like those.' She pointed at the rock overhang.

Axeman nodded, then, chimplike, turned his head one way and then the other, scampered round the diagram. Suddenly he leapt up and shouted an almost human sound.

'Home!' he said. 'Water home!'

Jo looked up at Sam and grinned. 'Let's just hope it's not a square rock.'

Sam stood up, then felt a sharp pain in her stomach. The world wobbled around her.

'Sam?'

'Just going to sit ' muttered Sam.

Then her legs gave way underneath her.

Mauvril watched as the honour guards burnt the curtains on the cairn of stones by the river. They were in full armour, lights glittering, polish gleaming, their eyes respectfully turned away from their commander. These were the curtains that had hidden the pictures of death.

No. The pictures of Tractite history Tractite history.

Oily smoke rose from the curtains: she remembered that they were made from some unnatural plastic fibre of human manufacture. Well, there would be no more of that. No more humans.

Kitig was a fool, thought Mauvril. A product of his culture. He'd never known anything but peace, civilisation, easy living. He couldn't accept his past, couldn't accept that all living was based on the blood of the dying. She ought to have him hunted down and shot but she knew she couldn't bring herself to do that.

Which meant she had no alternative. She couldn't have Kitig wandering around loose and the Doctor alive. One day, somehow, Kitig might contrive to get the Doctor out. It was improbable, but not impossible. It was too much of a risk.

Whatever she felt about the matter, it was a military necessity now.

She was going to have to kill the Doctor.

Now.

She saluted the guards, turned away and trotted towards the main dome.

'Wake up! Sam! You've got to wake up!'

OK, Doctor.

'Come on! I can't leave you! They'll kill you!'

Vampires, Zygons, hyenas, wolves...

Water. Warm, weedy-smelling water, running down her face.

'Sam!'

Jo's voice. Sam wiped the water from her face, felt precious drops trickle down her throat.

Hands touched her face. Cool hands, bristly, smelling of water and earth. Sam drank. When the water was gone she sucked greedily at the wet fingers, searching for more.

The hands were gently removed.

She opened her eyes, saw Axeman knuckle-walking away, chimp style, to scoop more water from the muddy pool. Jo was looking down at her.

'Can you stand up?'

Sam frowned. Her body felt as if it was separate from her, somewhere below her perhaps. She was aware that it ached, that it was hot and shivering and seared with cramp.

She put a hand on the ground, felt cool grainy earth. Pushed, and found herself standing.

'I can stand. I can walk. How far do we have to go?'

'Back to the gorge I think.'

Axeman had returned with more water. Sam sucked it out of his cupped hands, still greedy for more.

'I'm not sure you should be drinking that stuff. You could catch typhoid.'

'The TARDIS has antibiotics. If we don't get to the TARDIS fairly soon I'm dead anyway.'

That sounds suitably cool, thought Sam distantly: 'I'm dead anyway.' It's probably better not to think about what it means, any more than I'm going to think about 'If I fall over again, leave me. All right?'

Jo stared at her. 'No, as a matter of fact it's not all right. You're not '

What would the Doctor say? mused Sam, blearily.

Try this: 'It isn't just you and me. It's the whole future of the human race. The future of everything. You have have to get to the TARDIS and find the Doctor. You can't let me slow you down.' to get to the TARDIS and find the Doctor. You can't let me slow you down.'

Axeman was gesturing out across the yellow plain, towards the russet-coloured hill that was his home. Sam didn't need a translation: she started walking.

She felt as if she were pulling her own legs up and down with long strings, but the mechanism of her body worked. She moved forward, into the sun.

After a moment, she heard Jo start to follow her.

The eyes were just the same, staring at her from the same sunken sockets.

'You're here to kill me,' said the Doctor conversationally.

Mauvril said nothing. She could feel the weight of the human-made blaster she always carried, just as if it were the first time she had ever worn it.

'Kitig didn't like what he saw,' the Doctor went on. 'So he's gone and left you, so now you're going to finish me off, because you loved Kitig and you don't want to believe you aren't good enough to be his friend.'

Mauvril reached for the blaster. 'You're a danger to my species. To Kitig, to everyone.'

The Doctor closed his eyes. 'No I'm not,' he said. 'Just the opposite.' He sighed. 'You know, the real reason Kitig left isn't because you killed people, but because you're capable of killing people for stupid reasons like this. That's what he realised when he saw all those bones. Those people couldn't have hurt you '