Disclaimers: Don't own Sydney and Nigel.

Thanks for the reviews and to those who put this story on alert. Much appreciated.

And now a dedication: Happy Birthday to Ivoryrose. This can be your birthday fic!

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Despite the imagined onslaught of maniacal ponies, Sydney dropped off relatively quickly and slept soundly. It was after eight o'clock in the morning before either Sydney or Nigel awoke and realised that an early start was drifting fast off the agenda. By the time Nigel had finished his full English breakfast, complete with hash browns and worcester sauce, the sun was high in the cloudy sky. Sydney was getting impatient.

'I'm coming, I'm coming,' called Nigel, sprinting out of the door while still chewing his last piece of buttered toast. Sydney, raring to go in her stylish leather jacket and with her hair tied back in a ponytail, was already pacing down the public footpath. It wound off behind the pub and deep into the Great Forest. As she proceeded, she noted an ugly metal fire escape descending the far side of the building, right from the ledge of the sloping roof. 'So that's how they got in… and away,' she thought to herself, recalling the previous night's unwanted visitor. It was a timely reminder that this might be a rather challenging 'stroll' in the forest.

By this time, Nigel, who was wrapped up warm in a black wool coat and green scarf, had caught up with her.

'Have you got the key?' she asked.

'Yes. It's in my rucksack. And I've been doing some background research. That's what took me so long over breakfast.'

'Was it? I thought it was the sheer amount of food you consumed.'

'It was a good healthy breakfast - just what one needs with a long days hiking ahead!' Sydney shot him a skeptical look. 'It's got to be healthier than all those muffins and pancakes with maple syrup they serve you for breakfast on the East Coast!'

'I believe you, Nigel,' laughed Sydney. 'So what did you find?'

'Well, this Bishop Odo was a little strange, all right! Nobody knows anything about his background, but he had huge amounts of money and ended up master of Coombe Castle, over on the other side of the forest. What's more, he conducted some very dodgy rituals right here in the woods, where he used women priests - 700 years before the Church of England! He would have been excommunicated by the Pope, if it hadn't been for his pots of cash.'

Sydney was intrigued, and slightly amused: 'So Odo was a feminist Bishop?'

'Maybe. As for locating the staff itself, Giles' translation was… um, a little dodgy.' Nigel pulled a scrunched piece of paper from his bag and waved it in front of Sydney as she marched on. 'Giles thought that the key text he found on the medieval font meant: 'Life is found is at the heart of the complete number.' But I think he's misinterpreted the Latin word 'expletus.' In this context, it makes more sense if it translates as 'perfect.''

'Perfect numbers? You mean numbers that are equal to the sum of its divisors?'

'I think so. I thought it might relate to what you were telling me about the standing stones.'

Sydney regarded her assistant thoughtfully. Last night she had been checking out Giles' notes on the monoliths that he'd discovered in the forest. Each had Roman numerals carved on them. 'Life is found is at the heart of the perfect number,' considered Syd. 'So you think we need to look for markers with perfect numbers on them?'

'It's possible. In mediaeval thinking six was considered the perfect number, because it is the first one that is equal to all of its factors, but more importantly because God created the world in six days…'

'You're right. At least that's what Thomas Aquinas thought! It might be as simple as marking each number seven on the map and joining them together to find a mid-point. Then again, it might not be… '

Sydney glanced at her pocket GPS. 'Giles's marker was about three kilometres in this direction. Let's go.'

They headed off across a boggy water meadow that squelched underfoot. In the corner, huddled together under a little copse of trees, were three shaggy wild ponies. None stood more than three or four foot high, and their dirty cream coats were marked with brown patches. Even though the morning was bright, the ponies looked miserable and soggy, still damp after the night's rain.

As they drew closer to the little animals, Sydney recalled her dream and laughed.

'They're kind of cute!'

'What…?' Nigel was, metaphorically speaking, miles away. He was trying to recall all he could about mediaeval mathematics. 'Oh… you mean the ponies? No they're not. They're evil!' He silently growled in the direction of the little animals.

'Evil?'

'I got bitten by one of those little buggers once. It didn't break the skin, but it gave me the biggest bruise I had ever had… until I started going on adventures with you, that is. It was bright purple! '

Sydney laughed. 'Oh, Nigel! You must have provoked it in some way.'

'No, I didn't! It provoked me…' Sydney raised her eyebrows quizzically.

Nigel's words were bitter: 'I was on scout camp, right here in the Great Forest. Preston was my patrol leader – lucky me! - and we were having a picnic. He was always stingy with the rations, particularly with mine because he thought I was, well, you know…podgy. Anyway, he gave me one packet of crisps – one lousy packet of salt and vinegar crisps - which was supposed to last me all day! Then I saw the pony coming at me and I knew he was only after one thing…'

Nigel broke off, and his features set hard as he remembered the emotional strain of the moment.

'So did it get your potato chips?' asked Sydney.

Nigel barely heard the question as he continued with his tragic tale. 'That pony just kept on coming. I began to run away, but it was with several of its sneaky pony friends and they trapped me in the corner of the field. Preston just laughed - and then none of the others dared help.'

'Nigel, I didn't realise…' It suddenly occurred to Sydney that she might be making light of a particularly traumatic childhood experience. 'How old were you?'

'I was eleven,' continued Nigel grimly. 'I was terrified, but I wasn't giving in. I looked straight into that pony's eyes and I saw…' He took a deep breath, as if he was reluctant to reveal the awful truth. 'I saw a heart of darkness.'

Sydney could contain herself no longer. Chastising herself as it happened, she laughed out loud.

'They're just animals, Nigel. They're not really evil.'

'It was evil! Anyway, it stuck out its nasty great noggin towards my salt and vinegar crisps, and I pulled them away sharp. Then it bit me - right on the arm.'

They were now passing another little clump of the offending beasties; three were a fluffy chestnut brown, and a further one was pure, coal black. They appeared very contented, chewing away at grass and leaves. 'It must have been a rogue pony,' observed Syd. 'This lot seems peaceful enough.'

'Heart of darkness,' muttered Nigel, as a dumpy little filly swished her tail at him. 'Heart – of - darkness!'

………………………….

There didn't seem to be any ponies in the forest itself, just bare branched trees. Delicate miniature daffodils protruded from a carpet of fallen leaves, their bright petals lurid against the moldering brown of the dead foliage.

After a few reflective minutes trek into the increasingly thick undergrowth, Sydney's GPS bleeped.

'The stone should be somewhere around here.'

'Fine, let's have a look for it.' Nigel spied a large, prickly holly bush and groaned. 'I bet it's in there somewhere…'

He headed off to have a look, as Sydney snanned around. She was barely a few metres from where the device had bleeped, and was istening to Nigel cursing the thorns in the holly, when she found herself in a clearing.

'Hey, Nige. Take a look at this.'

Nigel extracted himself and was at her shoulder in an instant.

'It's the first marker!' He pointed to a small standing stone, not much more than a foot high, tottering at the edge of the clearing. It had obviously only recently been uncovered; the branches that had previously concealed it has been hacked away. Somebody had also scrubbed away enough of the moss to reveal some Roman numerals.

Nigel threw down his rucksack and ran over to it.

'Number seven,' he said, running his fingers over the markings. 'That's not a perfect number.' He pulled out his glasses and perched them on the end of his nose, in order to have a better look, and spotted some chalk markings over the indented number. 'Hmph. Look at this! Some philistine has scribbled some graffiti on it!'

Sydney was only half listening, busy inspecting the rest of the clearing. It displayed clear evidence of recent occupation. A fire had burnt to ashes in the middle; green leaves, white petals and a few stumps of candles were scattered around it. She noticed a strange, sweet scent, wafting on the air.

'It looks like Giles isn't the only person who has been here recently,' she muttered.

Nigel turned around quickly, absorbing what interested her. 'I wonder if somebody has used the clearing as a campsite? It was probably the same idiots who wrote on the stone.'

'Maybe,' replied Sydney thoughtfully. 'What's written on it?'

'It's just a scribble… oh, hold on.' He returned to have another look. 'Maybe it's a symbol. A circle with a cross sticking out the bottom. That's the ancient symbol for Venus… '

'… and the female.' finished Sydney. 'Maybe the women around here are finally getting some pride!'

'By defacing an ancient monument?' Nigel bristled visibly.

'I think it might mean something,' pondered Sydney. 'It looks like some sort of ritual went on here.'

A definite rustling came from the bushes on the other side of the clearing. Sydney turned with a start, spying a flash of white robe as somebody fled.

'Hey!'

Sydney plunged into the undergrowth after the spy. Twiggy branches flew in her face and thorns scratched her legs as she ran, hindering her progress. Nevertheless, wearing sturdy boots and tight black trousers, she was clad much better for running than her prey, who was encumbered with robes and sandals.

After a few seconds, she gained on them and grabbed the end of the white robe. It didn't pull away, but the wearer gave a cry - a decidedly feminine one - and tumbled to the ground.

'Professor Fox, please don't hurt me! I mean you no harm…'

'Who are you? Why were you watching us?'

No answer came. Sydney was about a haul her victim to its feet and make them talk, when the cry came from behind her.

'Sydney - come quickly! Aaaaargh!'

'Nigel!'

'Your friend could be in trouble…' The fallen woman's words came breathy and quick, but Sydney did not need to hear them. She cursed silently and charged back towards the clearing.

Before she could see her assistant, the yell came again, this time more desperate:

'Sydney!'

'Nigel! I'm coming!' As she burst into the opening, however, Sydney's fears that the white clad woman had been a diversion for a kidnap swiftly abated.

Nigel was still there, although he wasn't alone. He was standing on one side of the clearing, hugging his bag tightly, and staring daggers into the eyes of his persecutor: a particularly chunky, grey-coated pony. Although clearly wild like the others, it had a loose collar around its neck, attached for identification by the forest ranger. Its chin was adorned with a white, wispy beard and its mottled ears pointed forward like lopsided horns.

The pony was also looking at Nigel, but without the least alarm. Its teeth grinding from side to side, it chewed contentedly on a recent meal.

'I thought you were being attacked!'

Nigel screwed up his nose guiltily: 'I was… well, it wasn't exactly me. It was my bag…'

'Your bag?' articulated Sydney incredulously.

'I was about to chase after you, when I saw the beast enter the clearing out of the corner of my eye. I'd left the bag by the stone, and the evil creature cut me off at the pass! It has its nose in it before I could do anything. There was some food in the bag… '

'Are you trying to tell me that I let that woman get away to protect your mid-morning snack from a five foot high pony?'

Nigel grimaced again as he glanced into his rucksack, confirming the worst. 'It wasn't just the protein bars… he chewed on some of the research and…and…'

'And what?' demanded Sydney.

'I, um, I think he swallowed the key.'

'Well that's just great, isn't it?' Sydney glared at him. 'Can't I trust you with anything?'

'That's unfair! I told you, the ponies have got it in for me. They're evil!'

'They're just hungry, Nigel. You should have known not to leave your bag about with food in it.'

'Sorry,' muttered Nigel. He pulled out the mauled research and began smoothing it out against the stone, as Sydney regarded him, arms folded. He sighed heavily. 'You don't understand, Syd. It was like I was eleven again: that one pony felt like a whole gang of them. I could hear Preston laughing, and then I looked into its eyes…' He glanced up at the pony, which was still standing there innocently, and shuddered.

Sydney relented a little. 'It doesn't have a heart of darkness, Nigel.' She strode over and started helping him sort out the research. 'Sorry I snapped, but you need to get over this phobia…in fact, you're going to have to get over it quickly because we're following that pony until the key emerges at the other end.'

'Ugh!' This time, Nigel screwed up his nose in disgust. 'That could take ages.'

'Well it can't take any longer than two and a half days, or we will miss the window to open the secret chamber. We better find something to tether it up with.'

Nigel stared at her with a renewed horror. 'You can't possibly do that! These ponies were granted the freedom to wander the forest by William the Conqueror, no less. Tying up a Great Forest pony is a felony that still holds the penalty of death!'

'Death!? Oh, come on! That would never be enforced nowadays. Haven't you abolished capital punishment? Anyway, I know all about your mediaeval bylaws. Apparently, its still legal to shoot a Scotsman dead with a bow and arrow in the city of York. But I think if you actually did it, you might be in some trouble. '

'I still don't think we should tie it up,' said Nigel adamantly. 'At the very least it would be… bad luck.'

'Since when were you superstitious?'

'I'm not…oh, I don't know. There is just something about this place that gives me the creeps. Heaven knows why people choose to come here for their summer holidays!'

'I guess tying up a wild pony would be a bit cruel,' said Sydney, her thoughts heading off on another tangent. The pony had stopped chewing now, and was hanging its head wearily. 'Look, he's kind of tired after his meal. I don't think he's going to go far. We should go and try and find some other stone markers as quickly as possible, and then come back and keep an eye on him. Maybe if we can find a really long rope, it wouldn't be so bad…'

……………………………………….

Nigel and Sydney worked fast, and with some success. They found eleven other standing stones curving through the forest, two of which had number sixes on them.

'Two sixes might be enough!' observed Nigel as they uncovered the second one. He pencilled in the two locations on the map. 'As Giles predicted, the stones seem to be forming a circle, more like the one at Avebury than Stonehenge, but with smaller monoliths. If we join the two stones with sixes on them together, the midpoint might be the 'heart' we are looking for.'

He looked up from the map, perusing the small, limestone markers themselves. 'I still think that this stone circle is just as exciting as the medieval relic itself. If we can map it properly and prove its Neolithic precedent, this area could become nearly as famous as Stonehenge!'

'Yeah,' breathed Sydney, sharing his enthusiasm. 'I'm starting to believe it might have been worth the trip! But before we find anything else, we'd better check on that pony of yours.'

'Oh, that. I suppose we'd better.'

They dashed back to check that it was still asleep and where they had left it. After a moment of panic - the little nag was no longer in the clearing - they found it happily chomping at a bush nearby.

'Has it done its business?' asked Sydney. The pony let out a stuttering whinny, warily noticing their presence.

'How the hell should I know?' Nigel suspected he wouldn't like where this line of inquiry was going.

'Well, you'd better look for some evidence. The sooner we get the key back, the sooner we can leave the poor animal alone.'

Nigel groaned theatrically, and set about looking for piles of pony droppings. 'This is grose,' he complained. 'I can't believe we're searching for the key to a relic in pony poo.'

'You let him eat it!' pointed out Sydney. 'Besides, the droppings are just grass and leaves. It doesn't even smell that bad. It's sort of 'turfy.''

'It does to me!' moaned Nigel.' It smells of pony - it's enough to turn anybody's stomach.'

They both located piles of offending dung, and gingerly poked around with twigs and their boots. Even Sydney pinched her nose and cringed a little at a particularly fresh find.

Nevertheless, all they established was that no key had yet emerged.

'I have an idea,' said Sydney, pulling her location device from her pocket. 'These kinds of GPS tracking devices for hikers pick up each others signal if they're not too far off, in case anybody gets separated from the party. If I attach my one to the pony, we can use yours to navigate ourselves and keep tabs on it while we carry on with the hunt. We can even get the GPS to record the route it takes, so we can check any droppings. '

Nigel shrugged. 'Sounds like a good idea. How do you propose to attach it?'

'I thought I could somehow fix it to its collar…'

As if it understood her words, the pony instantly sensed it was under some sort of threat. Sydney crept calmly towards its side, but the little beast turned its bottom to her, puffed angrily and began scuffling its hooves.

'Careful Syd,' hissed Nigel. 'The devil might kick you!'

'It is not a devil,' emphasised Sydney. She backed away, nevertheless, realising she was not going to get close from this angle without gaining a large hoof-shaped bruise. 'Got any of those protein bars left in your bag?'

'There might have been a couple it didn't get its nasty little teeth around… oh God! You're not proposing I give them to it?'

'Have you got a better idea?'

'Oooh!' Nigel grumpily got out the bars and slowly unwrapped them. 'What you want to do?'

'Attract the pony's attention, and see if it will come to you and feed. I'll then try and attach the device.'

'It will have my fingers off!'

'Nigel!'

Nigel reluctantly obeyed, and whistled at the pony to get its attention. Turning its head slowly, the pony spied more of its earlier treats, and trotted over. As it approached, Nigel dropped the snacks to the ground and let it get on with it. He wasn't risking losing his fingers unless he really had to, not even for Sydney!

As the pony munched happily, Sydney quickly slipped the device onto its collar.

'Well done, Syd,' whispered Nigel. 'Let's get out of here before it retaliates.'

'I think we're quite safe now,' responded Sydney, echoing his hushed tone. She regarded the little creature affectionately. She secretly thought it was adorable - not as adorable as she quietly thought Nigel was - but cute nevertheless.

'We should give him a name,' she suggested.

'Why on earth would we want to do that? It would imbue it with some sort humanity!'

'It's harmless enough, Nigel. I think we should call it…'

'Stewie!' jutted in Nigel. 'We should call it Stewie. If we're going to name that thing, we should name it after somebody you really hate!'

Sydney laughed. 'Okay. Stewie it is!' She had been about to suggest the name of a rotund, comic character from a lesser-known ancient Mongolian legend, but she decided that Stewie would do. After all, as much as she hated Stewie, he wasn't really evil. He didn't, at least, have a heart of darkness…

…………………………………

Using maps and the single GPS, it didn't take Sydney and Nigel long to locate the 'heart' of the two perfect numbers. The spot was still in the woods, and didn't seem to be marked by any clearing. There was dense foliage but few nettles, which indicated that the ground had probably never been disturbed.

'Strange,' said Nigel, as he started rummaging around. 'I would have thought there'd be some sort of indication of earthworks, and that the ground would be more open. We might have to chop off a few tree branches if we're going to catch the sun on the first day of spring.'

'Yeah, strange,' echoed Sydney.

Sydney was becoming particularly twitchy: she sensed that somebody was following them.

'What is it?' hissed Nigel, picking up on her uneasy vibes. There was a distinct sound of breaking twigs not a few metres behind them in the direction that they had come.

'I think it might be more of our robed friends,' she whispered. 'Stay here.'

Silently as a deer, Sydney stalked into the undergrowth. A loud crunch came again, confirming her suspicions: somebody was definitely there.

Crouched behind the trunk of a fat horsechestnut tree, Sydney could see nothing. She waited until all was perfectly still, and then she sprang.

Poised with her arms and legs ready to spin into a defensive kick and blow, Sydney found herself face-to-face with her pursuer. The scruffy grey pony ground his teeth slowly as it chomped on some leaves.

'Stewie!' Sydney said the name with the same exasperation that she had uttered it with many times before.

'It's okay, Nigel,' she called, mildly embarrassed. 'The pony's been following us. I guess now we fed it, he thinks we're going to give it some more food!'

'Great!' came the reply. 'Now the bloody pony's stalking us. That's just peachy….' Nigel trailed off. She heard a scuffle and then his voice came again 'Sydney! Come quick!'

The cry was tinged with genuine fear. Sydney plummeted back towards which she had left him: her gut told her this wasn't just another of Nigel's pony 'friends'.

She was right. Sydney was confronted with the sight of two white-robed figures, neither of whom were the delicately sandaled female figure she had chased earlier.

One of them was delving through Nigel's rucksack. The other, wearing large black jackboots, was holding Nigel close against him with one chunky arm. His other hand held a distinctively carved knife to her assistant's throat.

'Syd…' Nigel had been the situation many times now, but he still looked terrified.

'Let him go,' snarled Sydney.

The reply came in a deep, querulous voice. 'Come one step closer, Sydney Fox, and your friend dies.'

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