'The story of my life,' she muttered, but she was smiling again. This was freedom, she supposed: to sit in your own kitchen, making a cup of your own cheap nasty tea.

The kettle boiled, and she poured water on to the alien-looking triangular bag. She prodded the sacklike body a few times with a teaspoon, then fished it out, added a drop of milk and took a cautious sip.

Too hot.

She slopped a little of the tea out into the sink, to make it easier to carry, then left the kitchen holding the mug in one hand. She'd got as far as the corridor when the phone rang.

Jo jumped. Automatically, she started towards the lounge where the phone was, but was halted when the ringing stopped and her ancient answering machine spluttered into life.

'Hi, I'm not able to answer the phone '

Quite, thought Jo. It's one o'clock in the morning, thank you very much.

She started towards the stairs.

The answering machine's speaker crackled. 'Is that Jo Jones?'

The voice was American, female.

Whispering.

Afraid.

Jo froze.

The line fuzzed for a moment, then, 'My name is Julie Sands, and I'm calling from a satphone in Kilgai, Tanzania, and I'm calling because we really need your help. I sent you an e-mail. I don't know whether you've got that but it's got worse.

This Captain Hynes has got Jesus, you're not going to believe me he's got an alien alien with him.' with him.'

What?

'Look, Rowenna's inside. I can't get to her and there aren't any police for miles. Oh, God '

A pause. Slowly, tea in hand, Jo started towards the phone.

'Jesus Christ he's dragging her out I think he's shot her.'

Jo almost dropped her tea on the carpet. She jumped for the phone, scrabbled the handset off its rest.

'What's happening there?'

Clattering sounds. Something which sounded like it might be a gunshot. The line fuzzed.

A mechanical voice. Faint, artificial, alien.

' get this one too '

'Jo, are you there? We need your help.'

A roar of static, then silence.

After a while, there was a click, and a dialling tone.

Jo stared at the handset for a while, her heart thumping.

Then she pulled the telephone notepad, the stupid one bordered with kittens playing in roses that Cliff had bought her on their first wedding anniversary after he'd left her, and scribbled: Kilgai, Tanzania Two women. One shot?

Alien, artificial voice. Not Dalek.

UNIT connection?

1. Contact UNIT 2. Get Matthew OUT OF THIS.

She hesitated. She remembered the Doctor's voice in her dream.

You'll have to help me, Jo.

OK, Doctor. You win.

She underlined the words 'OUT OF THIS' on the notepad, then lifted the phone and dialled a number she'd never thought she'd need again, but had somehow never forgotten.

Rather to her own surprise, she was smiling.

Regimental Sergeant Major John Benton looked at the screen and frowned. 'There's certainly something going on out there, Jo,' he said. 'We've got a team in Kilgai now.'

'Doing what?'

Benton sighed. 'You know I can't tell you that.' He nearly added, 'You shouldn't even be here', but thought better of it.

He and Jo had been through too much to allow a remark like that, even after all these years. He glanced at the decanters of whisky and gin on the polished wooden sideboard, and wondered if he should offer her a drink.

'Just give me some idea,' she was saying. 'Does it involve any of the known alien races?'

Benton shook his head. 'Come on, Jo. I don't make the rules.'

As Benton had half expected, Jo simply got up, walked round the desk, and looked at the screen for herself. 'You haven't changed, Jo,' he commented. 'Always ready to cross the front line.'

' "Kilgai, Tanzania. Incident class N",' she read. 'What's class N?'

'They divide incidents up into Y for "Yes, it does immediately threaten the existence of the human race" and N for "No, it doesn't".'

Jo laughed. 'You haven't changed, either. Or you wouldn't be able to say that with a straight face. Come on, what does it really mean?'

Benton felt himself blushing. For a moment he'd thought he'd managed to fool her. Suddenly he was twenty years old again, outclassed and outwitted by all the smart university people, the captains, the scientists, the brigadiers. 'I don't know what it means,' he snapped. 'They're always changing the categories. It's not my job to keep up with them.' He waved around the huge office with its regimental and UN flags, its silver swords and polished wood. 'All this is just a show, you know. I file reports, keep an eye on the paperclips, and tell the wives and kiddies when one of the lads cops it.'

Jo was silent for a moment. 'Do you really have to do that?' she asked.

'Twice in the last week. The captain couldn't do it himself: he's still out there.'

'Out where?'

'You know I can't '

'It's Kilgai, isn't it? And who's the captain? Jacob Hynes?'

Benton looked helplessly at the desk. 'You seem to know all about it already,' he said at last.

'The e-mail they were talking about mentioned Jacob Hynes by name. Julie said he warned them away from the area.

Look, that woman was afraid when she rang me. And she was afraid afraid of Jacob Hynes. A UNIT officer. You should at least look into it.' of Jacob Hynes. A UNIT officer. You should at least look into it.'

Benton picked up a paperclip that was lying on the desk and began bending it back and forth with his fingers.

'Jo, do you know how many hysterical reports of aliens we get at the front desk? Two hundred a day. I'm sure your friend met Captain Hynes at the gorge; I'm sure they found something strange that's probably why the team are there. But I don't believe that a UNIT captain '

'Do you know Hynes personally?'

Benton sighed. Jo was relentless, he thought. It was worse than dealing with the press.

'Not personally. But all UNIT officers are thoroughly vetted. You know that.'

Jo thought for a moment. 'Then it's probably mind control. It has to be mind control.'

The paperclip broke in Benton's hand. He stared at it for a moment, then said, 'Look, I'll contact Captain Hynes today '

'If he's just killed two women, he's not very likely to tell you the truth, is he?' A pause. She looked at the computer screen again. 'Can you check his personnel record?'

Benton shook his head. 'That's confidential, and you know it.'

The desk thumped, shook. After an instant Benton realised that this was because Jo had hit it. Hard. He looked up, amazed.

'What's happened to you, John?'

Benton wanted to say, 'I grew up. I got married, I have a wife and three kids and a job to hold down.'

But there were tears in Jo's eyes, and that stopped him from speaking.

'Listen,' she said. 'Those women could be dead. There's something going on out there. I need to find out what it is, and to do that I need you to make the arrangements. I know you can do it.' The big, brown, caring eyes fixed on his. 'Please, John.'

Benton looked away, not sure whether he was amused, embarrassed, or just plain irritated. This was getting ridiculous.

Jo had always been an impulsive person, but flying four thousand miles on the strength of a phone call struck him as taking impulsiveness to new dimensions.

'It's not on, Jo,' he said at last. 'If you're so sure there's something wrong, I'll contact Hynes's CO in Nairobi, ask him to look into the situation. That's all I can do.'

Jo got up, swallowed, looked at the floor.

'The Doctor asked me to help,' she said suddenly. 'He wouldn't have done that without a reason.'

'The Doctor Doctor?' It occurred to Benton that Jo might simply be lying, in order to get what she wanted. But if not 'Don't worry. I suppose I can pay my own air fare.' Jo turned, started across the plush Whitehall carpet towards the heavy wooden door.

Benton looked at his hands. If the Doctor was really involved 'All right, Jo,' he said. 'You win. You'll have to get to Kenya on your own, but I'll lay on a chopper from Nairobi to Kilgai. You'll be a guest of the regiment, out there to do your scientific research. But just remember, if you get it wrong if you put one foot out of place and start babbling about aliens that aren't there my career's on the line.'

Jo opened the door, then turned and said quietly, 'There's a lot more on the line than your career, John. I wouldn't be here otherwise.'

She went out, and closed the door behind her.

Benton stared at the cracked leather of his desk for a while, then picked up the phone.

CHAPTER 7.

The Tractite library was a greenhouse.

Sam stared at it in astonishment. She couldn't even see any books. The place was crammed with plants, and the air was warm and damp. It smelled of sweet perfumes, spices, and fresh flowers. But this was certainly the right building: the Doctor and Kitig were walking ahead along the stone path, chatting amiably. And she was sure the Doctor had said they were going to the library. They'd even discussed which books he was going to need to look at to establish where Tractite history had diverged from their own.

She peered ahead to see if there was any kind of inner building where the books were housed. But all she could see were the plants, some growing in huge, brightly coloured china pots, others from long beds of black soil dotted with leafy clusters. There were even full-grown trees, reaching all the way to the dark, translucent dome above. Plume-leafed species, pastel-coloured and clearly alien, were mixed with the deep-green tropical succulents of Earth. Fine sprays of warm water jetted down from the dark glass dome above, beading the leaves. There were flowers everywhere, creamy, sensual blossoms, long ropes of red and violet, a lemon-coloured tassel as big as Sam's head. A green, glittering movement caught Sam's eye, then turned into a butterfly with wings almost as big as her hands.

As they moved further into the building Sam at last saw books, but there was no sign of any shelving or organisation.

The books were scattered around in piles, some on stone tables under the dripping greenery, some on the paths, others on low, padded couches. Most of them were large and flat, like children's colouring books. Some, confusingly, were shaped like the leaves of plants. Tractites knelt at the tables or on the couches, chatting, reading the books, drinking what she guessed was green tea from large, brightly coloured china bowls.

'Lavender, you said?' the Doctor was saying to Kitig.

'Lavender with a hint of musk. I'm sure of it.'

They both sniffed the air, Doctor and alien, then moved suddenly up a flight of steps. Sam followed, but paused when she saw a book apparently discarded on the black soil under the roots of a pineapple plant. She picked it up, but the pages were glued together with damp, and the spine was rotting.

She hurried after the others. They were sniffing at a pile of books stacked by a fountain.

'Kitig,' she said. 'Where's the librarian?'

He glanced up at her. 'In the white robes, over there.'

Sam looked, saw a Tractite standing at a high stone table decorated with lilies and moss. He seemed to be reading two books, turning the pages quickly as if looking for something, and tasting the air with his tongue.

'Why do you need a librarian?' Kitig was asking. 'Hasn't that book been marked?'