Impossible or Improbable

The TARDIS materialises in a children's play area. Rose steps out holding a large red rucksack, which she slings onto her back. The Doctor follows, and they set off towards the flats on the Powell Estate with a spring in their step, obviously at peace with the world.

Inside the Tyler's flat, kitchen Jackie is doing the washing up when she hears Rose calling from outside the front door.

"Mum, it's us! We're ba-ack" Rose sings. Jackie, excited, hurries out to the front door, just as the Doctor and Rose enter the flat.

"Oh, I don't know why you bother with that phone! You never use it" says Jackie exasperated and pleased at the same time.

"Shut up, come here" Rose grins and they throw their arms around each other.

"Oh, I love you" Jackie smiles.

"I love you" Rose laughs

"I love you so MUCH"

The Doctor squeezes past them trying to sidle off, but Jackie's spots him

"Oh no you don't" Jackie grabs him "Come here"

She pulls him towards her and plants one on him, despite his weak protests.

"Oh, you lovely big fella" she squeezes him "Oh, you're all mine"

"Just- just-just put me down" the Doctor splutters.

"Yes, you are"

She kisses him again and then walks off, leaving the Doctor to wipe his mouth with the back of his hand, looking for all the world like a little boy with an over-affectionate mother. They join Rose in the sitting room.

"I've got LOADS of washing for ya" she says taking off her back and dumping it in Jackie's arms

"And - I got you this" She shows Jackie a tiny ornate bottle with a wide grin.

"It's from the market on this asteroid bazaar. It's made of um..." she turns to the Doctor "What's it called?"

The Doctor is flicking through magazines which are lying on the table.

"Bezoolium"

"Bezoolium" Rose repeats "When it gets cold, yeah, it means it's gonna rain - when it's hot, it's gonna be sunny! You can use it to tell the weather"

"I've got a surprise for you and all" Jackie smiles.

"Oh, I get her bezoolum - she doesn't even say 'thanks'" Rose rolls her eyes.

"Guess who's coming to visit? You're just in time - he'll be here at ten past! Who do you think it is?"

"I don't know"

"Oh go on, guess!" Jackie urges.

"No, I hate guessing. Just tell me" Rose puts her hand on her hip.

"It's your granddad, Granddad Prentice. He's on his way. Any minute" Jackie sound pleased.

Rose stares.

"Right, cup of tea"

Jackie disappears into the kitchen. Rose stares after her. The Doctor appears at her shoulder.

"She's gone mad" Rose mutters.

"Tell me something new" Doctor says still looking after Jackie

"Granddad Prentice - that's her dad. But he died like, ten years ago. Oh my God. She's lost it" she addresses Jackie "Mum?"

Rose and the Doctor stand in the kitchen doorway.

"What you just said about granddad"

"Any second now" Jackie mumbles.

"But... he passed away. His heart gave out. Do you remember that?" Rose asks gently.

"Course I do!" Jackie answers lightly.

"Then how can he come back?"

"Why don't you ask him yourself" Jackie checks her watch "Ten past, here he comes"

And right before their eyes, a figure steps out of nowhere in the middle of kitchen, it's featureless, like a shadow, but definitely humanoid. It stands beside Jackie.

"Here we are, then!"

The Doctor and Rose just stare, dumbstruck.

"Dad... say hello to Rose. Ain't she grown?"

The Doctor and Rose burst out of a side-door of the block of flats at a run. They come to a halt, looking around.

"They're everywhere!" the Doctor says confused.

Sure enough, the ghosts are everywhere, standing around just like ordinary people. No one seems to be remotely alarmed by their presence. A group of boys carry on with their ball game, just as normal. Rose turns.

"Doctor, look out!"

A ghost walks right through the Doctor, causing him discomfort but no pain.

"They haven't got long. Midday shift only lasts a couple of minutes. They're about to fade" Jackie tells them from behinds.

"What do you mean, SHIFT? Since when did ghosts have shifts? Since when did shifts have ghosts? What's going on?" The Doctor demands.

"Oh, he's not happy when I know more than him, is he" Jackie asks Rose.

"But no one's running or screaming or freaking out or" the Doctor looks around.

"Why should we" she checks her watch "Here we go. Twelve minutes past"

Jackie smiles at Rose, biting her lip with anticipation.

In a gleaming white room, a scientist pulls a lever down. A light dims down, and a woman takes off a pair of sunglasses, walking over to a younger girl who appeared to be at the age of seventeen, who was doing the same.

The ghosts disappear. The Doctor glances around, looking even more confused than he did before. The three of them head back to the flats.

The lever is pulled down fully. The engines die. Yvonne steps out of her office, which is separated from the busy main office/rift chamber with a glass partition. She smiles at the young brunette girl and addresses the staff.

"Ladies and gentlemen... I'd like to announce: we've just measured the ghost energy at five thousand gigawatts. Give yourselves a round of applause" She puts her hands together, and the rest follow suit all looking pleased except the girl whose sky blue eyes glinted with gold.

The Doctor is sat on the floor in front of Jackie's television. Jackie is sitting on the sofa and Rose is perched on the arm. They're all watching a programme called 'Ghost watch'.

"On today's Ghost watch, claims that some of the ghosts are starting to talk, and there seems to be a regular formation gathering around Westminster Bridge" the presenter says.

Cut to footage of the ghosts milling around Westminster Bridge.

"It's almost like a military display..."

"What the hell's going on?" the Doctor's brow furrows.

He changes channel to what would appear to be a weather report - but instead of weather symbols, there are little pictures of ghosts on the map of the UK.

"And tonight we're expecting very strong ghosts. From London, through the North and up into Scotland"

Turn over to the Trisha Goddard chat show. The caption at the bottom of the screen proclaims "I married a dead man!"

"So basically, Eileen, what you're telling me is, that you are in love with a ghost"

Eileen is sat in front of the studio audience with a ghost hovering around by the other chair.

"He's MY ghost and I love him, 24/7" Eileen says tearfully.

Encouraging round of applause from the audience, change channel

"Well, no one needs me anymore" Derek Acorah says.

Change channel. This time, it's a cheesy advert - a housewife in a flowery apron addresses the camera in her kitchen while a sad-looking animated ghost hovers around above the worktop.

"My ghost was pale and grey until I discovered... Ectoshine"

With an expression of complete bewilderment, the Doctor turns over. Now we're on a French news channel.

"Et le President d'aujourd'hui, quelle est"

Cut to footage of the ghosts wandering around the Eiffel Tower. Change channel - an Indian news report. Ghosts are milling around the Taj Mahal. Change channel to an enthusiastic Japanese Newsreader. The Doctor puts his head in his hands.

"Oh, yes!" Jackie grins.

Cuts to footage of three excited Japanese girls, all screeching wildly and showing off their ghost t-shirts.

"It's all over the world" the Doctor says.

An episode of Eastenders, Peggy Mitchell is behind the bar of the Vic, having a go at a ghost.

"Listen to me, Den Watts. I don't care if you HAVE come back from the grave. Get out of my pub! The only spirits I'm serving in this place are gin, whisky and vodka. So, you heard me - GET OUT"

The Doctor's had enough. He switches off the TV and turns to Jackie.

"When did it start?" he asks.

"Well first of all, Peggy heard this noise in the cellar, so she goes down—"

"No, I mean worldwide" he asks.

Rose smirks.

"Oh! That was about two months ago, just happened. Woke up one morning, and there they all were - ghosts, everywhere. We all ran round screaming and that; whole planet was panicking... no sign of YOU, thank you very much... then it sort of sank in, took us time to realise that... we're lucky"

"What makes you think its granddad?" Rose asks.

"Just feels like him. There's that smell, those old cigarettes. Can't you smell it?"

"I wish I could, mum, but I can't" Rose says sadly.

"You've got to make an effort. You've got to WANT it, sweetheart" Jackie smiles.

"The more you want it, the stronger it gets?" the Doctor asks.

"Sort of, yeah"

"Like a psychic link. Course you want your old dad to be alive, but you're wishing him into existence. The ghosts are using that to pull themselves in" the Doctor thinks.

"You're spoiling it" Jackie frowns.

"I'm sorry, Jackie, but there's no smell, there's no cigarettes. Just a memory" he shakes his head.

"But if they're not ghosts, what are they, then?" Rose asks.

"Yeah, but they're human! You can see them - they LOOK human" Jackie points out.

"She's got a point. I mean, they're all sort of blurred, but they're definitely people" Rose agrees.

"Maybe not, they're pressing themselves into the surface of the world. But a footprint doesn't look like a boot" the Doctor says thoughtfully and with that, he stands.

In Torchwood Yvonne and the girl approaches Adeola's desk.

"So, what've we got? Any sign of that power loss?" the girl asks.

"There's no problems must've been a glitch" she smiles but the girl thinks otherwise.

"Rajesh" Yvonne says on her communication device.

In torchwood, sphere chamber Rajesh is in his office with his feet up on the desk, immersed in a book.

"You got anything?"

"It's so busy down here, I'm on Sudoku book 509" he mutters glumly.

"Well, we just had a great ghost shift" Yvonne smiles.

"I know" he puts his book down "We had nothing"

He puts his book down and takes his glasses off, stands.

"Did they tell you?" he adjusts controls on panel "RND came up with a new spectrometer yesterday. Barged in here, all full of themselves..." he walks across the large chamber, checking various instruments "Said they could detect the heat off a single protozoa through half a mile of steel"

"And what did they find?" Yvonne asks.

"Nothing, it gave them nothing, same as ever. The machines keep saying the sphere can't exist. But there it is"

He's looking up at an enormous sphere, suspended eerily in mid-air at one end of the chamber. It is bronze in colour, and there's a step ladder positioned just below it to provide easier access.

"Anything we can do?" Yvonne asks.

"No, I'm all right. It's just... gets into your head, this thing. Like it's staring at you" he shivers.

The girl tenses.

"All right, we'll catch up later. Thanks, Raj" Yvonne laughs.

"Yeah"

He turns off his communication device, and then climbs up the ladder so he can reach out and place a hand on the bottom of the sphere - but it's as though there's an invisible barrier preventing him from doing so. He strains to break through it, but his hand is thrown aside. He gives up and climbs back down the ladder, defeated.