'We stick together,' Jack decided. 'There's something out here that isn't very pleasant. No one is to be alone, got that?' He looked at Rose and then Sofia. 'Are you two OK to get back to the inn and warn people?'

'Warn them?' Sofia shook her head. 'There will be panic. They will blame the Vourdulak.'

'Tell them what you have to, but tell them something.'

'We'll manage,' Rose a.s.sured him. 'Come on.'

'I'll find you at the inn,' Jack called after them. 'Then we should tell the Doctor.'

Alex Minin looked up from his paperwork to find the Doctor sitting in the chair on the other side of his desk. He gave a gasp of surprise.

'Didn't mean to startle you,' the Doctor said. Though his grin suggested he'd in fact meant to do just that.

'Can I help you?'

'Well, I've frightened Catherine and miffed Klebanov. So that leaves you and Boris.'

'And why not go to Boris?'

'He's less likely to have a spade.'

Alex put down his pen and leaned back in his chair. Somehow he got the feeling he wasn't going to like the answer to his next question. But he asked it anyway. 'And why, Doctor, do you need a spade?'

'Oh, nothing much. Just a bit of grave*robbing, you know.'

Alex swallowed. 'The previous victims?'

The Doctor was nodding excitedly. 'You can come with me if you want.'

'Doctor, it's the middle of the night. Never mind the dubious legality of the enterprise.'

'Nothing dubious about it. Completely illegal. No problem. Anyway,' he went on as he stood up, 'I need you to show me the graves. Come on, if you're coming.'

Alex stood up as well. 'Do I have a choice?'

'Nope.'

'I thought not.'

They were perhaps halfway back to the inn. With no light, it was hard to tell how far they had come and to Rose's untrained eye all the submarines looked the same.

'What will you tell them?'

Sofia seemed preoccupied, lost in her thoughts, and Rose had to ask twice before she got an answer.

'To stay indoors as much as possible and not to go out alone. Even in daylight.'

'Let's hope that's enough.'

Sofia did not reply. She stopped and raised her hand for Rose to be quiet. They were both hardly more than silhouettes against the snowy harbour road. Rose was about to ask what was wrong, but then she heard it too.

A slithering, sc.r.a.ping sound. Like something heavy being dragged across the road somewhere ahead of them. There was a faint mist now. The breeze had dropped and the cold night air was damp and clammy. It seemed to seep through Rose's coat and clothes and into her skin.

'What is it?' she asked in a whisper.

'I don't know.' Sofia was looking round, trying to identify exactly where the sound was coming from. 'You wait here.' She shone her torch into the misty darkness, though to little effect.

'Not likely,' Rose told her.

But then Sofia did something odd. Odd and strangely unsettling. She scratched at her ear a rapid movement, jerky, like a dog irritated by fleas. There was no reason why she shouldn't do it, nothing strange about the gesture at all. But it made Rose feel suddenly cold and alone. She wished she'd stayed with Jack and the soldiers. And when Sofia walked cautiously into the mist, in the direction of the sound that was now fading into the night, Rose stayed exactly where she was.

Sofia Barinska's m.u.f.fled footsteps faded into the mist, just as her shape had moments earlier. Rose was left alone on the quayside, hugging her arms round her body in an effort to keep warm. She stamped her feet and blew out long breaths of air that added to the thickening mist.

After what seemed like an age, Rose called out, 'Sofia? Sofia! Are you there? Stop mucking about and come back here, I can't see a thing.'

The sound was from behind her this time. The same slippery sound, like a weight of seaweed being pulled across the quay. Rose peered into the mist, but she could hardly even see the ground at her feet now that the moon was obscured. She moved slowly, cautiously, towards the sound.

Something was glowing faintly ahead of her. The light was blurred and unfocused in the mist. A torch, maybe? Jack and the soldiers returning? But if so, why hadn't the lights come back on? Or maybe they had. Rose remembered how few of the lights on the dock actually worked anyway. With the mist as well, the power might have come back on without her knowing. She continued to move cautiously forwards. The sound was still there, the light was getting brighter blue, pulsing, eerie.

'Do I want to do this?' she asked herself quietly. The answer was probably no, but she kept going. Until her foot met something and she almost lost her balance.

Rose knelt down, partly to see what was lying at her feet and partly to stop herself from falling over it. Even so, she could barely make out the dark shape. She prodded gently with her hand. Even through her thick glove she could feel that whatever it was seemed soft and slightly springy. Like a deflating balloon.

Like jelly.

With a sharp intake of cold breath, Rose was on her feet and backing away.

In front of her the pulsing, throbbing pale*blue light moved suddenly forwards coming straight at her.

SIX.

Whatever the light was, it made a slippery, slithering sound as it came. Something slapped past Rose, brushing her shoulder before flopping down on the ground at her feet. There was another sound now something dragging. The body she had found being pulled back, towards the light that was now brighter, pulsing more rapidly. A tendril of glowing blue swept in front of Rose, making her dodge sideways and stagger backwards.

She didn't wait to see any more of the creature. She turned and ran. Straight into a dark shape that solidified out of the mist and held her tight.

'What is it?' Sofia demanded as Rose pulled away.

'There's... something. Back there.'

'What sort of something?'

Rose gave a short laugh. 'A nasty something. I didn't hang around to find out any more. And another body, I think.'

'You think?'

'Well, you've got the torch.'

The slithering sounds seemed to have stopped and Rose led the way cautiously back towards where she had seen the glowing creature.

'Like a blobby blue jellyfish or something. With, like, tentacles, you know.'

'I don't think I do.' Sofia sounded nervous too.

But there was nothing there. The faint torchlight picked out the trail in the snow where something had dragged itself up onto the quay and along the roadway. And the deeper trail where something heavy had been pulled away.

'One of the soldiers?' Rose wondered. 'Jack couldn't get them on the radio.'

'If so, this man wouldn't have been alone,' Sofia pointed out.

'More than one, then. Maybe. Oh, I dunno, do I?' Rose protested. 'We should be getting back to the inn.'

Sofia was shining the torch along the trail. It was little more than an impression in the snow no distinctive markings or footprints. Almost as if someone had rolled a s...o...b..ll along.

'You say it was glowing?'

'Yeah.'

'But the snow hasn't melted. It's just been pushed aside and crushed.'

'So, it glows but it doesn't get hot. It was sort of bluish.'

'Not even warm. A few degrees above freezing is hot round here.' Sofia clicked her tongue, considering. 'That's why we need the generator working again, and quickly. Not for light so much as for heat. Though the inst.i.tute has its own power supply if we get really desperate.'

'Jack'll sort it.'

'I hope so.' She shook her head. 'Too much,' she muttered. 'Too much, too soon. I'm not ready for this.'

'Who is?' Rose wondered.

Sofia seemed to gather herself and come to a decision. 'I want to look at the stone circle again, where we found poor Pavel's body.'

'What, now? In this fog?'

'It may be clearer up on the cliff. This is a sea mist. It won't be so thick higher up.'

'Even so.'

'I want to see if there's a similar trail up there. If we wait, the snow may obscure it.'

'It probably already has,' Rose pointed out. 'And if it hasn't, the soldiers have been trampling all round the place anyway.'

'You don't have to come,' Sofia said. She turned away. 'Go back to the inn and keep warm and safe there, if you like.'

Rose sighed. 'I'll come,' she said. 'You'll need someone to keep an eye out for angry blobs while you go poking about in the snow.'

A light came on about ten metres away. Its glow was dissipated by the fog. It flickered as if struggling to stay alight, then brightened slightly. It wasn't much, but it was a comfort. Rose could see that Sofia was smiling. But the way the shadows and the mist obscured her face, for a moment she looked almost grotesque. Like a grinning skull. Then she moved and the moment was gone.

'Come on, then,' Sofia said.

They took one of the Jeeps from the inst.i.tute. Minin drove, silent for most of the journey. It was more than just his concentrating on getting through the thickening mist.

'You got a problem with this?' the Doctor asked at last.

'Several.'

'I'll take the blame.'

'That's only one of the problems.'

'So what are the others?'

'Least of our problems will be digging through frozen ground. More of a problem is knowing where to dig.'

'Someone must know. We'll get directions.'

Minin wiped at the inside of the windscreen with the back of his hand. It made little difference. They had slowed almost to a walking pace.

'Fedor Vahlen will know. He digs the graves.'

'How's he do that?'

'He's a builder. Mainly repairing leaks and shoring up the older buildings. But he's got a digger.'

'That's OK, then.'

'Pavel was his son,' Minin said quietly.

'Oh. Right.' The Doctor thought about this. 'He should be glad to help, then.'

'Might be glad to help you you. Vahlen and I... he doesn't like me.'

The Doctor turned to look at Minin. 'No one likes you,' he pointed out. Then he grinned. 'He'll like me, though. Everyone does. Guaranteed.'

Razul was rubbing his oily hands on a rag. 'There was a blockage in the main feed from the larger fuel tank. No wonder they had to keep topping it up. Should run for a couple of days now without needing any attention.'