'Yes,' said Jessica, 'it was the first thing I noticed when I came in. I thought it was just the fact that the house had been unoccupied for so long.'

'It probably is the reason. It'll be interesting to see if every room is the same, though.' He ignored the faint smile on the face of the medium. 'Miss Kirkhope's agent has managed to supply me with a geological map of the area as well as a two-and-a-half-inch scale survey map. One will tell us the type of soil the house is standing on and the general structure of the land around it; the other will show if there are any streams or wells near the property. Tunnels or underground streams beneath the house could cause the chill or perhaps you would call it "atmosphere", Mrs Metlock.'

'I most certainly would,' the medium said, still smiling. 'I felt it immediately I entered. But I hope you do find some physical reason for it, Mr Bishop.'

'Then I want to test the structure of the house itself. No plans of the building are in existence, unfortunately, but I'll do my own survey. I want to know the materials used in its construction, test the walls for damp, look for shrinkage of any kind.'

'It seems you need a more practical knowledge for your work than just experience of the paranormal,' Kulek remarked.

'Practical knowledge outweighs any other as far as I'm concerned. I used to be a planning surveyor before I took up chasing ghosts, and I needed to know just how houses got themselves built for that.'

'And when you have done all this?' Kulek asked.

'Then I want to set up some equipment to be left here overnight.'

'Equipment?'

'I want to know if there's any activity in this place when it's supposedly empty. I intend to set up a camera connected to a tape-recorder, linked up to photo-electric cells and a sound and vibration detector. If anything moves or makes a noise in this house tonight, we'll know.'

'But you can only set this up in one room,' said Jessica.

Bishop nodded. 'This will be the room. For the others I'll have to rely on powder and black cotton. If we find traces of disturbance in any other room, we'll move the electrical equipment into there for the following night.'

'Have you considered staying overnight in Beechwood yourself?' It was the medium who posed the question.

'Sure. And my considered reply to myself was "no".'

'But I thought you didn't believe in ghosts.'

'I don't believe in being uncomfortable.' He turned to the girl. 'Jessica, I've brought along two thermometers, the greenhouse kind. It would save time if you tested one room while I did the same in another.'

'All right, shall we start down here?'

'No, upstairs. I want to get an idea of the general layout first. Jacob, do you want to come with us?'

'I'll stay and keep Edith company. I'm afraid I wouldn't be much help to you.' He smiled encouragingly at his daughter and Bishop.

Bishop picked up his case and told Jessica to follow him. He paused at the foot of the stairway, looking up into the sombre greyness of the landing above.

'I suppose there's no electricity?'

'No, we tested the lights when we came in,' Jessica said.

Bishop shrugged. 'I didn't really think there would be.'

He climbed the stairs, taking two at a time, his strides swift, leaving the girl hurrying to keep up. He stopped at the top and waited for her.

'That's where I found the first body,' he said, nodding towards the balustrade. 'It was hanging from there.' He saw her shiver.

'Did you come up here, to any of these rooms?'

'No. Just into the main room downstairs. That was enough.' He walked to the end of the landing and drew back the curtains. Light sprang in but made little progress along the hallway.

'Come on,' he called to her and she joined him at the foot of another staircase.

'Two upper floors,' he commented, reaching into his case and producing a torch. 'The principal bedrooms will be on this floor and upstairs will probably be what was once the servants' quarters. There's enough light to see by, but we'll need the torch for looking into cupboards and suchlike.'

His progress up the second staircase was slower and Jessica was able to keep close behind him. There were four doors on the landing above, all closed. Once again he walked to the window and drew back the curtains, a strong musty smell from the material irritating his nasal passages. The daylight revealed the hatchway in the ceiling and he flicked on the torch, shining its beam upwards.

'I'll have a look in the loft later,' he said.

Jessica tried the handle of the door nearest to her. It turned easily and she gave the door a gentle push. The small room was devoid of any furniture, the floorboards bare, dark with age. A tiny, iron-framed fireplace faced her. Bishop pushed past her and walked over to it, crouching and shining the torch up the chimney. He withdrew his head and said, 'Can't see too much. I can't tell if it's blocked or not.'

'Is it important?'

'I need to know where any draughts come from. Or if there are any birds nesting in the chimneys. Our feathered friends are often the cause of "ghostly flutterings".' He took a thermometer mounted on a thin block of wood from his case and looked around for a suitable peg to hang it on. He settled for resting it on top of the small mantelshelf above the fireplace, placing it in an upright position, top resting against the wall. Then he produced a ten-by-eight sketchbook and a felt-tipped pen. There were no curtains at the window, so the light was adequate for his purposes.

'I'm going to make a plan of each room,' he explained, 'then an overall plan of the house. I'll mark on it any draught points, holes that shouldn't be there, rotted floorboards and any structural alterations from the original building. You can help by looking for any signs of dampness.'

'Shall I start in here?'

'No, take this other thermometer into the next room. It'll save time if we move them on when we get a stable reading.'

Jessica took the instrument from him and left the room, stopping for a moment outside. Somehow there seemed to be less light in the hall than before. It was almost as if dusk were falling. That was silly, she told herself. It was still mid-morning. The clouds outside had become heavier, that was all. She moved along to the next door and twisted the handle.

It turned easily enough, but when she pushed against it, the door barely moved before meeting resistance. Jessica pushed harder and the door seemed to sink into something soft yet resilient. This time she put her shoulder to the door and gave it a short, sharp shove. It moved inwards about an inch. She put her eye to the gap, but it was too dark in the room to see anything clearly. Her gaze travelled down the crack and she could just make out the shape of something bulky lying across the bottom of the door. She dared not admit to herself what it might be.

'Chris,' she called out, keeping her voice steady. 'Could you come here for a minute, please?'

He came from the room and frowned when he saw the anxiety on her face. She pointed to the door.

'There's something blocking it.'

He tested the door, pulling it back then pushing against the unseen object. He felt the wood sink into something before meeting firm resistance. Jessica's features were not clear in the poor light, but he could see her eyes were wide.

'It feels like . . .' she said.

'A body? Don't let your imagination run away with you. It could be anything.' Nevertheless, there was a prickling sensation around his scalp.

He gave the door a hard push using the weight of his whole body and it swung inwards six inches. 'Get the torch,' he told her and she quickly disappeared into the other room. He pushed again, keeping up the momentum of the swing, and the door opened wide, one foot, two, a slithering noise accompanying its movement. He took the torch from the girl and stepped halfway into the room, keeping the beam low. Jessica watched his back as he leaned forward and peered around the door. It seemed so dark beyond him.

He looked back at her, a broad grin on his face. A curled finger beckoned her, then he disappeared from view. As she slowly crept forward she could hear his footsteps crossing the floor, then the sound of material being swished back. Dull grey light filled the room.

Jessica stepped sideways through the gap and breathed out when she saw the rolled carpet lying at an angle across the floor, one end resting against the open door.

'This kind of house can make you imagine all sorts of things, Jessica,' Bishop said, one hand still on the heavy drapes he had just pulled back from the window. There was a softness in his voice that she didn't expect from him.

'I'm sorry, Chris. You're right about the house, though: it does stir the imagination. It's so gloomy in here.'

He drew nearer to her. 'The carpet must have been standing in the corner over there. Some disturbance perhaps when the police were here last made it topple and block the doorway.'

She managed a weak smile. 'I'll try not to be so shaky from now on.'

'Don't worry about it. It's happened to me in the past. I've come to learn there's generally a rational explanation.'

'And the times when there isn't?'

'That means I haven't been clever enough to discover it.'

Before he could snap up the barrier between them again, she reached for his arm. 'Tell me, Chris, why were you so angry when you found Edith Metlock here?' She saw the coldness flicker behind his eyes.

'It was a surprise to me. I think you're well aware of my feelings towards such people, yet you asked her here.'

'But she's a genuine sensitive. Her reputation is beyond reproach.'

'Is there such a thing as a genuine sensitive? I've no doubt she thinks she is and her belief in the spiritual world is quite sincere. But how much of it is real and how much comes from her own subconscious? I'm sure she is clairvoyant, but then again, couldn't that just be the power of her own mind?'

'It could be, I'll admit that. Whatever it is, it seems to work.'

He smiled at her and some of the antagonism between them melted.

'Look,' he said, 'I've been pretty rude to you and your father not to mention Mrs Metlock. I'll try to keep my opinions to myself while this investigation is going on and I promise to keep an open mind to whatever we find providing you and your father do the same.'

'But we have.'

'No. Your father seems to be obsessed with this Pryszlak and his view could be clouded by what he knows of the man and his work.'

'My father is totally objective.'

'If he was, he would have brought in a headshrinker to help me remember those forgotten minutes, not a spiritualist.'

She realized he had a point and kept quiet.

His voice was gentle when he spoke. 'I'm sorry, I didn't mean to bark at you again. I'm only trying to make it clear that there are two sides to this and I happen to be in a minority of one. If there is a connection between this house and all the recent killings in the road, then I'd like to find out what it is, too.'

'Let's work together, then, not against each other.'

'Agreed.'

She looked away from him and, for a moment, he felt she was flustered.

'Okay,' he said, 'set the thermometer up over there then let me know the reading on the other one before you move it on to the next room.'

They worked their way systematically through the upper floor of the house, recording the temperature of each room, checking for draughts and damp, Bishop making detailed drawings. They descended the stairs to the main bedrooms and followed the same routine. The rooms on that floor were much larger than those at the top of the house, but the low temperature seemed constant throughout: five degrees centigrade. The rooms themselves, although in good repair, had the musty smell of emptiness, the creeping decay of walls without the echoes of life.

Jessica stood alone in one room waiting to take an accurate reading from the thermometer she had placed in there moments before. She looked at the solitary bed, its bare springs somehow heightening the loneliness of the room. She wondered why they hadn't taken away the few remaining pieces of furniture and decided they probably meant nothing to Miss Kirkhope neither financially nor for sentimental reasons. When the house came down, then the contents would undoubtedly be crushed along with it. She moved to the window and watched the road below. An old woman shuffled by, not even giving Beechwood a passing glance. A cyclist came into view, his head down, scarf tight around his neck, pedalling steadily, vapour breaths dissolving fast in the cold air. An ordinary suburban street. Like millions of others. But behind certain walls, a difference.

Jessica turned from the window and crossed the room. She stooped to pick up the thermometer propped against a wall and her face creased into a look of consternation. The temperature had dropped from five degrees centigrade to below zero. Even as she watched, the mercury crept down, the movement slow but visible. When it had reached ten degrees below and was still sinking she placed it back in position and hastily went to the door.

'Chris!' she called out.

'In here.'

Jessica ran to the next room. He had his back to her, scribbling notes on to the sketch he had just made.

'Chris, the temperature next door is dropping rapidly. It's unbelievable. I can actually see it going down.' She was suddenly aware how cold she felt physically.

He turned in surprise, then strode towards the thermometer in that room. 'Christ, you're right,' she heard him say. 'It's below twelve in here.'

The scream made them both jump. It came from the rooms below, screeching its way up the staircase and echoing around the landing walls.

For a frozen instant, Jessica and Bishop stared at each other, then, as one, they raced towards the stairs. Bishop reached them first and as he descended he sensed a blurring before his eyes, shadows hanging like cobwebs in front of him. Jessica saw him sweep a hand before his face as though brushing aside invisible curtains. She followed close behind, but could see no obstruction.

Bishop almost stumbled halfway down, missing a step as though avoiding something lying there. Jessica could see nothing.

He swung round the banister at the bottom of the stairs, then staggered against the opposite wall, a look of bewilderment on his face. Jessica reached him and held him steady. They ran onwards as another scream pierced through the suddenly cloying air and reached the room in which they had left Jacob and the woman. Bishop stopped in the doorway and collapsed on to his knees, his face draining of blood.

The room was filled with people. Their bodies, many naked, writhed and twisted in agony, features contorted as if they were screaming their pain, but no sounds coming from their lips. A woman, near enough to Bishop for him to reach out and touch, swayed unsteadily, her head swung back, beseeching the ceiling. Her blouse was open, the buttons torn away, heavy breasts thrusting the material apart. She wore no clothes from the waist down and her fleshy thighs trembled in some strange paroxysm. Her fingers were curled around a small glass and he could see the whiteness of her knuckles as she strained against it. The glass shattered and its few drops of liquid mingled with the sudden gush of blood from her cut hand. Bishop flinched as spots of blood spurted against his face and he pulled back when the woman fell. She landed in front of him, her back still heaving.

His eyes darted around the room, widening with each individual scene of horror. On the floor, not five feet away from him, three figures were locked in tight embrace, one on top of the other. Their naked bodies shook, but he could not tell whether it was from pain or ecstasy. He realized it was a woman underneath, her legs spread wide, arms scratching at the arms and backs of the two men above her. One had entered her and was moving his hips in unison with the man who clung to his back and who had entered him. The woman's face was pointed towards Bishop, but he could see her eyes were glazed as though heavily drugged. A heavy-set man lumbered towards them, his clothes open to display his genitals. Wild hair and beard almost obscured his face, but Bishop could see this one's eyes were sharp, obsessed. In his hand he held a long, pike-like object, its length black and tapering gradually to a fine point. He held the point against the back of the man uppermost in the tangled heap, pressing it slowly down until it punctured the skin and a tiny drop of blood oozed out. The naked man paid no heed to his injury, continuing to press into the man beneath him. The man with the pike reached upwards and closed both hands against the flat base of the weapon. Bishop opened his mouth to scream as he realized what was about to happen, but the cry stayed locked deep inside his chest. The bearded man plunged downwards and the long, black point sank from view, the pike descending into a fountain of red liquid, its length smoothly disappearing until the man's blood-stained hands were only inches away from his victim's flesh. All three bodies went rigid with shock, then continued trembling, this time the movements jerky, spasmodic, reaching separate crescendos before falling limp, unmoving. Bishop could see the bearded man laughing, but still no sound came to him.

A young girl, probably in her early twenties, struggled with two men on the room's worn settee which stood beneath the high, bow window. They held her wrists and legs. Her skirt was pulled up around her waist and a woman knelt before her, pushing something bulky between the girl's thighs. The girl looked down at the object, her eyes wide with pleading and Bishop saw the tape sealing her lips. She arched her body and the trapped end of the object rose with her. Bishop raised a hand towards them, but it was as though he was engulfed in a sticky fluid that hindered his movements, bearing down on him with a debilitating force. He saw the woman squeeze the twin triggers of the shotgun and closed his eyes when parts of the girl's body ruptured through her clothes. Even the shotgun blast was silent.

A hand touched his shoulder and he opened his eyes again. Jessica was standing over him, her lips moving.

A man stood behind the door, an insane grin on his face. Liquid drooled from the corner of his mouth and the glass he held slipped from his fingers, landing on the floor without breaking, rolling away from him, then back in a semi-circle. The man slid down the wall, still grinning, his lips only curling down in an expression of painful horror when he reached the floor. His back was stiff against the wall when he slowly toppled sideways, the action like the movement of a second hand against a clockface. His legs kicked out, once, twice, and his chin receded into his neck as his jaw opened to its fullest extent, not even relaxing when he was dead.

A group of men and women sat around the table at the far end of the room, their hands joined across its surface. They waited patiently while one man walked around behind them carefully slitting their throats with a butcher's knife as he went, each member holding on tightly to the hand of the dying man or woman next to them until forced to let go because of their own dying. Soon none of the hands was joined as the bodies lay slumped across the table or had slipped from their chairs. The man who had done the slaying calmly ran the knife across his own up-stretched throat, his chest becoming sodden and red as he sank back to his knees; he fell forward on to his face.

Bishop tried to rise, the girl, Jessica, tugging at his arm to help. A man was watching him from the armchair in which Jacob Kulek had been sitting. His face was thin, cheeks hollow, shadowy, and his eyes seemed to protrude unnaturally from his skull as though he suffered from meningitis. The lips were thin, unformed, the line of the mouth curled at one end in an expression that could have been a smile or a sneer. His hair was black but sparse, swept back from his forehead, making the distance between his scant eyebrows and hairline seem extraordinarily long. His elbows rested on either arm of the chair, his hands raised steeple-shaped before him, a small glass of clear liquid held at their apex. His lips parted as though speaking, then he looked away from Bishop towards a man and woman nearby. They were coupled together, the woman holding the man's head down between her thighs while he thrust himself into her throat. They were frail with age, the skin hanging loosely over prominent bones; their hair was white and brittle.

The mallet was wielded by the bearded man, who laughed when the old man's skull cracked under the blow, his head becoming wedged between his partner's skinny legs. The bearded man knelt beside the aged couple and brought the mallet down hard on the man's buttocks, the woman beneath him suddenly struggling to free herself from his choking member. She twisted her head to one side, but the force of the blows pushed the man's pelvis against her, smothering her, pinning her neck at an awkward angle. It was impossible to know if she died from suffocation, a broken neck, or just shock.

The bearded man was laughing gleefully as he rained blows on the now still bodies. He stopped abruptly and looked towards the man sitting in the armchair. The man was speaking to him, but Bishop could not hear the words. The bearded man shuffled on his knees towards the seated figure, the mallet still grasped tightly in his hand. The glass of clear liquid was offered to him and he took it, hesitated, looked deep into the contents. Then he drank.

The sneer or was it a grin? on the seated man's face deepened and he looked towards Bishop once more. He picked up something that had been lying in his lap unnoticed by Bishop. It was heavy, black. A gun. The man took a long, sweeping look around the room, his bulging eyes finally coming back to rest on Bishop. His lips moved, then his mouth opened wide; the muzzle of the gun was pushed in, pointing high into the roof of his mouth. Everything around Bishop seemed to slow down, all movements losing speed, the struggles becoming graceful, a ballet of death. It took a lifetime for the man's finger to slide around the trigger and pull it back tight against the guard, the recoil blurred but still slow, the flame lighting up the inside of his mouth so that Bishop saw the hole appear, could almost follow the bullet's path as it travelled through the man's head, erupting on the other side, carrying bits of brain, mucus, blood, into the air to shatter high against the wall behind leaving a red smear of dripping substance.

Bishop stared at the running pattern and traced a trail of slow-moving blood back to the man below. But it was not the same man. The eyes still bulged, still stood out from their sockets, but it was fear that made them so. Fear of the unseen, sensed only, for the eyes were sightless. It was Kulek who now sat in the chair.

He was calling out and the sounds came creeping through to Bishop. It was as though Kulek was at the end of a long, winding tunnel and was drawing near, his voice becoming louder and louder at his approach. The figures around Bishop became misty, ethereal, their twisting and writhing becoming even slower until they were still; and as they faded, so another body became clearer, more defined. Edith Metlock lay slumped against the wall, eyes closed, head hanging limply sideways. Kulek's cries came fully to Bishop's ears and with them he found the strength to raise himself, staggering back against Jessica who tried to support him.

He whirled around and she fell to one side, gasping sharply as she went down on one knee. Bishop had to get out, had to get away from the house and the terrible thing that had happened there. That was still happening.

He fell against the door-frame, his body swinging round at the impact so his eyes were looking down into the far end of the hall. There were more moving shapes, fading, slowly dissolving, their bodies grey in the dim light. He pulled himself upright and cried out, 'No!' when he saw the legs hanging above the stairway. They kicked out wildly, scuffing the wall, a shoe falling loose and rolling down several stairs before coming to rest. Dismembered hands clutched at the fading legs, tugging at them, pulling them downwards till they no longer kicked. The hands faded away and only a dim twitching outline of the limbs remained.

Bishop had to get away from the house. He knew the slaughter was going on all over; in the bedrooms upstairs; in the rooms on the second floor. He had to get out. He began to run towards the front door, his legs leaden, his breath drawn in short, sharp gasps. The door beneath the stairway was ajar, a long, narrow gap beckoning to him.

He stopped running and pushed his back against the opposite wall as he had once before. And, like before, the door seemed to be moving outwards as if someone were pushing it from the other side. He found he was reaching forward in repeat motion, his fingers clutching the door's edge, afraid to look, but compelled to, something down in that cellar commanding him to. He pulled the small door back and it swung wide, the blackness lurking behind it shuddering and falling away at the sudden light, dim though it was. He heard a movement. A shifting sound. Something on the stairs below. He had to see. Had to.