Spring was a busy time for Gita Chandra. Her flower shop, Blooming Lovely, was transformed every week and sometimes more often than that as she anticipated special events and produced themed displays to capitalise on them.

There was Valentine's Day, of course. But very quickly after that was Chinese New Year, followed by St. David's Day, Mother's Day and Saint Patrick's Day.

"Oh dear!" Rani sighed as she approached the shop.

"What?" Clyde asked her. "Oh... yeah, it’s a BIT over the top, isn't it!"

He grinned as Rani pushed open the shop door and stepped inside, neatly side stepping a bucket of plastic shamrocks on long sticks. The same bucket had contained plastic daffodils not so long ago.

"Mum, this is a complete tackfest," Rani exclaimed as she looked around at the bouquets and wreaths with green as their theme colour, tied up with ribbons of orange and white.

Shamrock was a major sub-theme. There were bunches of shamrock-shaped balloons, shoes, maps of Ireland, wheelbarrows and all sorts of shapes made of real shamrock on wire and oasis, shamrock shaped flower arrangements and even shamrock shaped arrangements of shamrock.

Plastic shamrocks were planted in every bucket of cut flowers and every wreath and arrangement around the shop.

But even they weren't as corny as the plastic leprechauns on sticks that peeped out of almost every clump of green in the shop.

Gita was putting the finishing touches to a life-size harp made of fresh green, white and orange flowers.

"Who on earth is going to buy THAT?" Clyde exclaimed as he watched Gita arrange the huge floral piece opposite the front door for maximum effect.

"For your information, Clyde Langer, that piece is already SOLD," Gita responded. "In fact, it was a special bespoke order. They’re picking it up any time now."

"Who is?

"Mr Eoin McGann of the Ealing Irish Centre. It’s a special gift for their guest of honour at tonight's St. Patrick's Day party - Niamh O'Dowd."

"Wow!" Clyde was impressed despite himself. Irish harp music was definitely not his thing, but Niamh O'Dowd had topped the charts three times in the past year with harp renditions of rock classics and her album had broken the record for length of time in the top ten. It was a coup for the Ealing Irish Centre to get such a performer on a special night like this.

"So that's for her, then?" Rani asked, impressed that her mother had garnered such a prestigious commission.

"Aren't you the investigative journalist!" Gita remarked. "I just said that. It's taken me all day to make, but it’s a real honour to be asked. My reputation as a florist is spreading, my darling. I could be as famous as you, soon."

"I'm not famous," Rani answered her. "I'm still a junior writer on the Guardian. The scoop about the Pearl Dress was just sheer luck."

"Whatever you say, darling. Anyway, the concert is going to be on BBC3. My design will be on stage next to Niamh as she performs. It's rather exciting."

"It's brilliant, mum," Rani assured her. "I still wonder about all this, though - theme flowers. I mean... two weeks ago it was all daffodils and Welsh dragons, now its shamrocks and leprechauns. Some people might find it all a bit insulting. You're cashing in on their culture."

"Oh, I don't think so," Gita responded with her usual blinkered enthusiasm for her own projects.

"Well, if a gang of militant Irish dancers descend on you tonight and challenge you to prove you have Celtic ancestry, don't say we didn't warn you, mum. We'll be off. Clyde and I are going to the National Gallery for the afternoon. There's a special exhibition on and I've got a press pass. There's a buffet and drinks afterwards and we thought we'd do a concert later - as long as it has nothing to do with Irish harps."

"Have a nice time," Gita told them. "Don't worry about getting home too early. Your dad is cooking his 'special' tonight."

Rani looked at her mother with a worried expression, Clyde with a thoroughly appalled one.

"Mrs Chandra, that is too much information!" he declared.

"What do you mean, too much?" Gita retorted. "All I said was...."

Then her attention was caught by a row of St. Patrick's Day floral shoes - actual shoe sized arrangements of real, living shamrock. They were jumping off the shelf one by one, accompanied by a shrill voice that seemed to be saying some odd things.

"My harp!" Gita cried out as the line of falling shoes rapidly closed in on the floral arrangement she had spent so much of her time on. But Clyde had already leapt into action. He grasped the harp in both hands and dived out of the way. Meanwhile Rani grabbed a flower pot and brought it down on top of something she had spotted moving along the back of the shelf. As she trapped the strange thing it uttered what sounded like some colourful swear words, though she wasn't quite sure.

"Is é seo an gréasaí ann? An bhfuil tú an ngréasaí?" The thing demanded from within the pot.

"What is it?" Gita asked. "A rat or something?"

"It's... something like that," Rani assured her.

"People have been complaining all week about them," Gita said. "Mr Bloomberg at the paper shop said they were coming out of the building site - you know, where they're refurbishing that old cinema. I blame that new Thai restaurant, myself. Have you seen the rubbish round the back. The health authorities ought to be on to them."

As Gita launched into a monologue about the hygiene issues of Ealing Broadway, Clyde carefully put the harp arrangement back on its stand before doing his best to recover the shamrock shoes. Most of them were bent out of shape and the oasis water was all over the floor. Gita told him not to worry. The important thing was that he had saved the harp - something that had already earned him enormous future son in law points from her.

"Mum, we would stay and help clean up," Rani said. "But we have to get to the gallery. I'll... get rid of the rat on the way."

She clamped a small tray under the plant pot and quickly upended it, trapping the 'whatever' inside.

"Tú soinneáin ar an diabhal!" came the cry from within.

"Behave yourself, or I'll chuck you in the dustbin," Rani answered in a low but threatening voice as she stepped out onto the street with her strange prison held carefully in her hand.

"Ah, an mhallacht ar dom ar feadh amadán, a gabhadh ag aghaidh go leor! Chun an diabhal a bhfuil tú bean, pláigh ar gach do theach."

"And don't think I can't understand what you're saying, either," she added. "Clyde, I think we might have to miss the gallery. We need to go back to Bannerman Road and talk to Sarah Jane. You'd better drive. I don't want to let go of this thing."

Clyde accepted all of that without argument. He was disappointed about the changes to his itinerary, but this was clearly something important, and Sarah Jane was definitely the woman to see about it. He reached into Rani's pocket for her keys and earned himself a colourful insult from the creature in the plant pot.

"The thing is," he whispered close to the pot. "Rani and I have both travelled in a thing called the TARDIS, which among other things lets us understand languages. 'May the Devil blast your thatch' isn't much of a curse, really, even in London where it might mean setting somebody's hair on fire. "

The creature replied with something stronger. Clyde rapped on the tray.

"I know what THAT means, too, and if you say it again in front of my girlfriend, or the very polite lady we are going to visit there will be trouble for the one of us who fits in a plant pot. Do we understand each other?"

A quieter response suggested that the creature understood. The journey to Bannerman Road was quiet and uneventful.

Sarah Jane was finishing up a Skype chat with Luke when Rani and Clyde came into the attic. K9 made an unexpected alert noise and declared the proximity of an unknown organic being.

Sarah Jane picked up a small device from a side table and scanned the flower pot before telling Rani to put it down in front of Mr Smith. A small beam enveloped the pot.

"It should be quiet enough, now," Sarah Jane said, nodding at Clyde to take the tray off the pot. He did so and all three of them looked at the subdued creature inside, caught in a mild stasis field that kept it from running away but didn't completely knock it unconscious.

It didn’t stop it from using colourful insults involving the Devil and various body parts.

"I warned you," Clyde said. "Not in front of the ladies."

"What is it?" Rani asked.

"It's a leprechaun," Sarah Jane answered.

"Really?" Clyde queried. "Seriously."

"Seriously," Sarah Jane assured him.

"It... doesn't LOOK like a leprechaun," Rani pointed out. "At least not like the two hundred plastic models my mum ordered for her St. Patrick's day displays."

"That's just fiction," Sarah Jane explained. "THIS is what leprechauns really look like."

This was not at all like a tiny but otherwise normally shaped man. it was more like a swamp green hairy ball with spindly limbs poking out. The word 'gonk' embedded itself into Rani's mind, but usually those were brightly coloured and slightly more endearing than this creature.

"Is that why it was going on about cobblers?" Rani asked. "When it was making a mess in mum's shop it was going on about wanting the cobblers…. Because it’s a leprechaun and they do shoe-making?”

"Actually, I thought it was just being rude," Clyde pointed out. "At least he was trying to. 'Cobblers' is a Cockney swear word, but I'm not sure the Irish word for it is."

"It was speaking Irish, of course!" Rani observed. "Sometimes it is difficult to tell when languages are translating in my head."

"You get used to it," Sarah Jane told her. "I think it is possible he WAS looking for a cobbler. Before your mum opened Blooming Lovely, the shop WAS a branch of Timpsons. But a leprechaun has no business being there any more than a flower shop. They're not supposed to be in London, or any populated area. They ought to be confined to a sparsely populated valley in the West of Ireland where they can't bother anyone."

"Who made that arrangement?" Clyde asked. "I mean, I didn't know we had immigration restrictions on bogy-coloured fluff."

"The Irish branch of Torchwood did it in the early nineteen-twenties," Sarah Jane replied. Both Rani and Clyde were interested - even intrigued. They were among the very few civilians who knew that the secret organisation to monitor and control alien threats to Earth existed, but it was news to them that Torchwood had overseas offices.

"They had people all through the Empire when they were founded, " Sarah Jane confirmed. And a few other places, too. Anywhere except America. But, anyway, in 1920, as you should know from school history, or at least from the film with Liam Neeson, Britain and Ireland were negotiating the terms of the Irish Free State. They had settled on boundaries, fiscal policies, the designs for stamps, the colour of the flag and special preferences for Britain's imports, all the things that matter to politicians - when the whole thing was almost ruined by a deputation of leprechauns demanding their own terms."

"You're having us on," Clyde remonstrated. "April Fools is still two weeks away."

"I'm not, I absolutely assure you. The leprechaun contingency demanded plenipotentiary status at the meetings on the grounds that they had lived in Ireland longer than any humans and should have a say in the matter of how it was governed."

"Considering the mess humans have made running the country, maybe they had a point," Rani suggested.

"Unfortunately not," Sarah Jane answered. "Their proposals were mostly concerned with illegal distilling and cattle rustling - both to be made legal for leprechauns in the Free State. And if they didn't get what they wanted they would run amok in London, Belfast and Dublin, drinking all the whiskey they could get their hands on, stealing horses and scaring children."

There was a snigger from the plant pot and the captive within made it clear that scaring horses and stealing children was just as much fun.

"That's not funny, at all," Rani answered it back. "Shut up or I'll give you to K9 for a chew toy."

"I do not chew, mistress Rani," K9 pointed out, but the threat hit home, anyway.

"Well, obviously something had to be done. So Torchwood Ireland used a pagan binding ritual along with a bit of alien technology to confine the entire leprechaun race to a five mile radius of a really old oak tree that stood in a field near Maam Cross in County Galway. The binding also prevented them from doing anything that drew human attention or in any way revealed their existence. That meant no mischief of any sort except baiting the occasional drunk that nobody would ever believe."

"Leprechaun ASBO, brilliant," Clyde remarked.

'So what went wrong?" Rani asked. "Ealing is a lot more than five miles from Galway."

"I really don't know," Sarah Jane admitted. "But we have to do something about him and his clan. These days scaring horses isn't the worst they might get up to."

Again there was a snigger from the plant pot.

"Oh, be quiet, you," Sarah Jane told it. "Or K9 can have you for target practice."

"I do not need target practice, mistress," K9 remonstrated, but nobody took any notice of him.

"So he's some kind of advance guard from an invasion force?" Clyde suggested. "And we should take it seriously?"

"Yes, and yes," Sarah Jane assured him.

"Then, the first thing we need to find out is how they got out of Galway and where the rest of them are."

"And what the plan is."

The plant pot rocked with the laughter from within.

"Éist anseo, tá tú amadáin ceann mór, nach bhfuil Sean ag rá leat rud ar bith! Níl Sean ag rá leat focal. Níl Sean insint, fiú a ainm do na cinnirí mór Béarla."

"That’s all right, Sean," Sarah Jane answered as the leprechaun proved, like so many prisoners before him, to have the right to remain silent but not the ability to do so. "We have other ways of getting information around here."

"Gan an céasadh uisce! Ní Sean deoch uisce, ach amháin uisce beatha!"

Clyde put the tray back on top of the plant pot and weighted it down with a Venusian paperweight - a cube no more than an inch wide but weighing several pounds. That secured the prisoner while they gave their attention to Mr Smith. He had monitored some urgent calls to the emergency services from Ealing business proprietors that needed their attention.

"I never knew that Ealing was so Irish," Rani commented as Sarah Jane parked the Lime-Green Figaro in the bay outside a café called 'An Crúiscín Lán ' which had rather pretty, if a little kitsch, jugs and shamrocks all around the picture window. The window was not looking as picturesque as it ought to be just now as it appeared to have been in the line of fire during a pantomime style custard pie fight.

Inside the evidence of some kind of confectionary battle continued. Every surface was covered with cream or remains of cakes. one full sized Victoria sponge was still sliding down the front of the counter.

A very shaken woman was relieved to see anybody prepared to listen to her.

"The police said they couldn’t get anyone out to me until after four o'clock," she said, introducing herself to Sarah Jane and her companions as Alma Klaasen.

"That’s an interesting name, Sarah Jane said. "Dutch, isn't it?"

"My parents were Dutch," she explained.

"But this is an Irish themed café. Do people not think that odd?"

"It belonged to my late husband," Alma explained wearily. "His family were from Donegal. The name means 'the full jug.' I suppose it really doesn’t matter. If I changed it to a Dutch themed café I'd be expected to wear clogs and a Dutch bonnet and play Windmills from Amsterdam all day. That would be no more authentic than this. Anyway, I've always done all right. Today, I was doing a nice lunchtime deal on coffee and shamrock-themed cup cakes. Then... suddenly... the whole tray tipped off the counter. Nobody was anywhere near it at the time. The cakes just started launching themselves at the walls, the window, the customers. Everybody ran away, screaming. I don’t know if they'll come back...."

Sarah Jane asked several questions about the phenomena while Rani and Clyde slid behind the counter with Sarah Jane’s sonic screwdriver and a large metal jug. There was a clang and a suddenly cut off stream of Irish language obscenities before Clyde triumphantly took the captured creature out of the café.

The same situation prevailed at the bakery where the cup-cakes were made and decorated. Rani and Clyde captured five more leprechauns there while Sarah Jane interviewed a manager and four workers who were covered from head to toe in butter cream and icing sugar after the attack from an invisible enemy that muttered strange things at them throughout the assault.

Two more cake shops had the same story.

A card shop selling St. Patrick's day cards and the same sort of balloon and plastic shamrock kitsch that Gita Chandra had indulged in had its whole stock reduced to colourful confetti.

The worst hit was a pub called Pogue Mahones. The wooden box loaded with twenty miscreant leprechauns was shaking with mirth at the pseudo Irish name. Clyde couldn't help a wry grin.

"Actually I knew that joke even before TARDIS travel," he said. He knocked on the lid of the box. "I know it isn't spelt right. It's still just as rude in translation so snicker away."

He left two more alien paperweights on top of the box and followed Sarah Jane and Rani into the pub. This time there HAD been a police visit. A licensed premises under attack had to be investigated.

It looked like a war zone. Every window, mirror, glass partition or drinking glass had been reduced to fragments that crunched underfoot. The floor was wet with spilt beer and spirits as the taps and optics were opened and allowed to overflow. The manager sat on the only chair that was left with all four legs intact and stared around in disbelief.

"Excuse me," Rani said to him. "I can’t help noticing... you're Korean."

"Yes...." He looked at Rani as if about to accuse her of some kind of racial slur, but changed his mind.

"Well, this is an Irish pub," Clyde pointed out gently.

"It is in Ealing, and qualified bar managers don’t grow on shamrock trees," the manger responded. "I got the job because I could pull a pint, keep order on a Friday night and do the books, not because I could sing Molly Malone while standing on my head."

"Fair enough," Clyde agreed. He watched Rani capture the two creatures responsible. They were in the sink under the optics where they appeared to have been bathing in whiskey - and drinking quite a lot of it as well. They were the easiest but loudest captives, singing Molly Malone, off key, as they were carried out to the car.

Clyde noticed something about the situation, but decided not to bring it up just yet.

When they got back to the car, though, he opened Rani's laptop and plotted all of the incidents of vandalism on Google Earth.

"Interesting," he said. "All of the attacks are within a five mile radius of the Ealing Irish Centre."

"Any other day I would call that a coincidence," Sarah Jane told him.

"The Centre hasn't been attacked," Rani confirmed, checking the list of affected businesses.

"The centre is genuinely Irish, run by Irish people for the benefit of Irish people and culture," Clyde continued. "Everywhere else - the pub run by a Korean manager, the Dutch lady with an Irish café, the bakery and card shop... even your mum, are all sort of.... fake."

"Is that what this is about?" Rani asked. Inside the box the two drunk leprechauns sang a very dirty song about 'plastic paddies' while the rest joined in the choruses.

"Well, that's a bit silly, isn't it?" Sarah Jane considered. "After all, as the manager pointed out, he was qualified for the job. To refuse him it on grounds that he wasn't Irish would be... I don’t know... racist?"

"But it's like that with these things, isn't it?" Rani continued. "Chinese takeaways are run by Chinese people, Pizzerias by Italians, tapas bars by Spanish men with sexy accents who look good in black t-shirts and little aprons..."

Clyde and Sarah Jane both looked at Rani as if they thought she had give TOO much thought to tapas waiters.

"Well, they do," she continued defensively. "And if my dad went into an Indian restaurant and found it didn’t have Indian waiters he'd walk out again in disgust. He isn't racist, but he expects his curry to be authentic and served according to Indian hospitality. All our different cultures have their own different specialties. But EVERYONE jumps on the Irish bandwagon, especially today with all the green Guinness and shamrock cup-cakes and everything. It’s like I said to mum about the a gang of militant Irish dancers. I was joking, but what if that's how these little guys really feel about it all?"

Clyde thought about what Rani had said, then rapped on the box for attention.

"Ok," he said loudly. "You lot have a point. Too many plastic paddies, especially today, of all days. But on the other hand, St. Patricks Day is the only saints day that gets this much attention all over the planet. Being English on St. George's Day is boring. Most people don’t even remember the date. But everyone wants to be Irish, because it is mega cool and you rock. You ought to be proud of that. Being Irish is the coolest on this planet.”

There was a brief discussion inside the box, and then a single voice was raised in apology.

"Bhfuil muid leithscéal. Muise, ní bheidh sé tarlú arís."

"That’s better," Sarah Jane told them, accepting the apology wholeheartedly. "Now let’s get you back where you belong."

"To Galway?" Rani asked.

"Not yet," Sarah Jane answered. "Just to the Irish Centre."

The centre was doing far less to advertise St. Patrick's Day or its Irishness than any of the other places they had been to, - even Gita's flower shop. There was an Irish tricolour flying above the entrance and in the foyer there were green ribbons and real shamrock buttonholes on sale with the proceeds going towards a London-Irish homeless shelter. That was about it.

"I think mum made those," Rani admitted as Sarah Jane bought shamrock buttonholes and they pinned them on before going through into the ballroom.

Here, too, taste prevailed. The theme was green white and gold and there was extra bunting around for the special day, but it wasn't at all over the top or garish.

It was as if the Irish centre was doing it best to set a standard in décor that was ignored by the rest.

On the stage, Gita Chandra's beautiful flower-harp which had been delivered while they were interviewing cake-covered confectioners looked magnificent set next to a real harp of burnished oak and gold finishings laid carefully on a stand.

The lady famed for playing the instrument was just finishing a rehearsal piece using a smaller, hand-held harp. She put it down and stood to meet Sarah Jane and her young friends. Clyde had a moment a bit like Rani and the Spanish waiters before pulling himself together in front of the beautiful and poised Miss Niamh O'Dowd.

"I think we've met before," she said graciously to Sarah Jane. "At the reception for the Inauguration of President Higgins."

"Yes," Sarah Jane answered. "You played beautifully. But that was just a social occasion for me - one of the genuine privileges of a lifetime in journalism. This time, I'm afraid it's business."

"Oh dear," Miss O'Dowd sighed. "It's THEM, isn't it. I hoped we might get back to Ireland before there was any trouble."

She looked past Sarah Jane to see the box of stray leprechauns turned upside down and skittering across the beautifully clean floor like the most peculiar forty-legged hermit crab. Miss O'Dowd reached out a delicately booted foot and stopped them. The box tipped slightly and dozens of eyes looked out from the gloom.

“Ah, ‘tis the harpy woman,” said one of them.

"That’s harpist not harpy,” Niamh responded sharply. “I told you lot, no shenanigans or you'll get nothing but skimmed buttermilk for supper. Away with you, now, into the dressing room, and not another word."

"You can see them," Clyde observed as the box scuttled away. "None of the others could, not Gita Chandra or the bar manager or the people being pelted with cakes."

"Because none of them were really Irish," Rani guessed. "We're the exceptions, because of The Doctor and the TARDIS and all that. Otherwise, only Irish people can see them."

"But it doesn't explain how they got here. They still seem to be bound to the five mile limit, but it is focussed on this building."

"You're not from Galway, are you?" Rani asked Niamh.

"No, Roscommon," she answered. "But that harp there IS from Galway. I think that's what you're looking for."

Everyone looked at the harp - the real one, not Gita Chandra's flower arrangement. It was so beautiful Rani wondered how Niamh dared to play it for fear of damaging it.

"I have three concert harps," she continued. "My first is too old and delicate to be transported around to concerts, now. It's the one I learnt to play as a girl. The other is the famous 'Eamon', named after my first boyfriend. It's the one I played on my first two albums and at the inauguration, as well as at the Royal Variety Performance last year. This is my newest harp. I called it Ciaran, after my LATEST boyfriend. It has a history all of its own. The wood came from a seven hundred year old oak tree that stood near Maam Cross until last winter when it was blown down in a gale. The wood was saved and made into this very harp, which was given to me when I was awarded the Freedom of Connaught for services to Irish music."

"Huho," Clyde murmured.

"Yes," Sarah Jane agreed. "It was the tree Torchwood Ireland bound the leprechauns to. They weren't allowed to go beyond five miles of it. But now that the tree has moved, so do they."

"I knew nothing about all of that until I brought the harp from Ireland," Niamh admitted. "As far as they were concerned coming to London meant the 'no mischief' part of the deal was up, at least. Did you hear about the Aer Lingus plane that had to make the emergency landing at Gatwick yesterday evening? That was them. They got upset about coming to England and tried to sabotage the landing gear. They only stopped when they realised they'd be killed, too. I made them stay in the dressing room, here, and they were behaving at first. Then somebody sent me a bottle of Irish pear brandy as a welcome gift and they sampled it... and that was it. I was worried sick about what was going to happen. I thought I really ought to call off the concert and go back to Ireland."

"I think they’ve learnt their lesson," Sarah Jane assured her. "Please do carry on with tonight's concert. When you do go back home, though, you'd better call the Dublin Torchwood team. They can find another suitable tree and redo the binding. You can't be responsible for that entourage everywhere you go."

"It would be a great relief not to have them hanging around," Niamh admitted. "Oh, dear, what about the trouble they caused? Do you think a few free concert tickets might make amends just a little?"

"I'm sure that would help," Sarah Jane told her. "Though Rani's mum might not need one. I understand Haresh is cooking his 'special' tonight."

"Did she tell the whole street?" Clyde asked as Rani just blushed and looked away. "Tell you what, if you're going to do some of those cool rock classic numbers, I wouldn’t mind a couple of tickets. As long as the furries accept that my only connection with Ireland is a U2 album on my iPod."