The House That Jack Built: The House That Jack Built

'Not quite. That machine was a quantum transducer that allowed you to see images outside your own temporal fixed point. That's actually more of a Time TV than a ghost machine.'

'Time TV?' Gwen raised an eyebrow.

Jack smiled. 'Residual haunting is the idea that emotional events of sufficient potency give off a wave of energy that is stored in solid matter — an old house, a murder weapon, a site of historical violence — and are then picked up later like psychic radio and re-experienced by someone sufficiently attuned to those frequencies. It was put forward as a theory in the early 1960s. It's been a popular explanation for ghosts ever since.'

'Popular? Not correct?'

'Not quite. Matter and energy just don't work that way. Taking for granted that emotional outbursts can be stored in physical matter — which they can, but in a such a weak and fragile form that most dissipate quickly — the human skull exists as an insulator against stray electromagnetic fields bombarding the brain. We'd be freaking out every time someone turned on a mobile phone otherwise.' He shut up for a second, concentrating on avoiding a group of teenagers crossing the road. One of them stuck their middle finger up at him as the drag from the vehicle sent him off balance and into the gutter.

'You missed,' Gwen said.

'Better luck next time.'

'So… skull as an insulator…?'

'Yeah, basically we pick up on the vaguest of emotions: deja vu, maybe a sense that you're not alone in a room… nothing concrete, nothing visual. For that you'd need one hell of an amplifier. Cardiff's sat on one with the Rift, of course, but even then it would take an incredibly focused burst of energy to visualise something without some pretty nifty equipment.'

'But it's possible?'

'Oh yeah … and not just in Cardiff. Most hot spots for ghost sightings have some kind of external influence at work — Borley Rectory, the Treasurer's House in York… both the sights of some pretty major temporal fallout. It's not always natural, though. I remember this old museum in Stratford-upon-Avon, built its whole reputation on the amount of supernatural sightings within its walls… The owner was bombarding the place with hallucinogenic theta waves, hoping to summon up Shakespeare. People were tripping their rocks off the minute they crossed the threshold.'

'What did you do?'

'Locked him in his own gift shop for four days. Poor guy was convinced he was Oliver Cromwell by the time I let him out. He's probably back to eating solids by now… Anyway …' He turned into Penylan Road. 'The point is: it takes a lot of factors to come together in order to provide an actual physical manifestation, and even then it's worth checking it's not something altogether different…'

They were distracted by the flashing lights of a police car and an ambulance. The woman that Ianto had seen killed earlier was being zipped into a body bag and carried away from the scene.

Jack wound down his window and called to one of the police officers. 'What happened?'

The policeman looked him up and down. 'You lot, is it?' He checked over his shoulder to make sure nobody was listening. 'Looks like hit and run, woman was knocked over coming out of the shop over there, dragged halfway up the road, right state she is. No bugger saw anything, of course, but it doesn't take Quincy to piece it together. Unless you know different?'

Jack smiled. 'Of course not.' He shoved the SUV back into first gear. 'Just passing by. See you around.'

'Bloody hope not.'

Jack wound the window back up. 'Let's hope that's a coincidence, shall we?'

'Violent death? Coincidence? Us?' Gwen didn't believe it for a moment.

'Ianto's the priority. Everything else can wait.'

Around the corner, Jack swung the SUV off the road and into Jackson Leaves' small forecourt. He was out of the vehicle before Gwen had so much as unclipped her seatbelt. She joined him at the door as he rapped insistently on the wood.

'Can you smell onions?' she asked as they waited for someone to answer. When nobody had after a few seconds, Jack opened the door and stormed inside.

'You don't still own the place, you know,' Gwen said, following awkwardly.

'Now's not the time for formalities,' Jack replied, looking around the hall. 'Hasn't changed much… Hello?' he shouted. 'Mr Wallace? Ianto?'

There was a sound of movement from behind one of the doors and he ran forward, storming into the lounge and narrowly avoiding the poker Rob swung at him as he crossed the threshold.

'Rob Wallace, I presume?' Jack said, pulling the poker from the panicked man's hand and holding up his own in a gesture of surrender. 'The door was open…'

TWELVE

The knocking on the door, coming so soon after the noise that had surrounded them, wasn't the relief to Rob and Julia that it was to Ianto, still barely able to move as he lay on his back in front of the unlit fire.

'What did he say?' Julia asked, looking at Ianto and fully expecting another onslaught of apparitions to attack them.

Rob grabbed the poker from beside the hearth. 'Nothing that makes me feel any better.'

'It's all right…' Ianto whispered, his chattering teeth cutting the words into brittle sounds as they tumbled from his mouth. 'Let them in…'

They heard the sound of the front door opening, and Rob turned to face the lounge door, poker in hand. 'So you say…' he whispered, tightening his grip on the brass handle. He was sick of being on the receiving end of the night's many impossibilities.

He heard the intruder shouting his name.

The door opened, and Rob prepared to fight his way past whatever was behind it. The poker was out of his hand before he had even been truly aware of swinging it.

'The door was open…' said the intruder.

'I saw you before.' It was Julia, putting her hand on her husband's shoulder as she spoke to the newcomer. 'You were with the police.'

'Sort of,' Gwen stepped into the room. 'We work with them occasionally.'

Jack pushed his way past Rob and Julia, dropping to his haunches by Ianto.

'Hi there, frigid,' he said with a smile.

'Sod off,' Ianto stuttered, 'and get something to warm me up.'

'Now may not be the time or place…' Jack turned to Rob and Julia. 'Got any alcohol?'

'No…' Rob was struggling to maintain any feeling of being in control. 'I was lighting a fire…'

'So light it.'

Rob stepped forward before anger stopped him. 'Look! What's going on here? You say you're with the police?'

'Not as such,' Gwen tried to force her face into the most reassuring shape she could manage, used to being the politician among them. 'We're independent of them. But yes, our paths cross from time to time. Why don't we sit down and go through what happened?'

'I'm not staying here a minute longer,' Julia said.

'We saw a woman appear out of thin air…' Rob shouted. 'Killed herself in the bath… not in our bathroom you understand, no, in the spare bloody bedroom…'

'There's a fat man…' Julia added, 'in an old suit… he smells…'

'Banging on the walls, voices in the TV…'

'Your friend, appearing out of nowhere in our airing cupboard…'

'Our bloody airing cupboard!'

Their voices were getting louder and louder, blending into one another.

Gwen knew if they carried on she'd never get them under control. 'Please!' she shouted. 'One at a time… We