Author's Note: thank you to everyone who has read and reviewed this story, it means a lot. The usual disclaimers apply and I own none of this. Thanks again, and reviews would be a welcome.

Chapter Four: Numerology

Lucas knew he was dreaming again. It began before he was even fully asleep; a film reel of suppressed memories, playing itself out once more. It started in the same place; immobilised against the cold tiles, the smell of disinfectant strong enough to make his eyes water beneath the cotton cloth that shrouded his face. Slow dripping water, gradually got faster until he was sucking the cold fluid deep into his lungs, tricking his brain into thinking he was drowning. The burning in his lungs intensified rapidly, until a sudden rush of air cleared his throat as the towel was whipped off. Then, the scene changed as an unbidden memory re-awoke from his past.

The shock temporarily woke him, just as a fist pummelled the pillow mere inches from his face. He choked for air, before sinking back to the floor on which he slept, straight back into the dream as if there had been no interruption. A smartly dressed woman, not a hair out of place, looked down at him as she paced a wide circle around his prone figure. His eyes marked her progress, distracting him from the cold and the heavies who bore down on him. Casually, she drew on a cigarette as she came to a halt at his bound feet.

"Tell me, what is Sugar Horse?" she asked between puffs, a trail of acrid smoke snaking from her mouth and nostrils as she formed the words. "What is Sugar Horse?"

"I don't know what Sugar Horse is," he rasped back at her between panting breaths. "I. Don't. Know."

A naked light bulb flickered overhead, keeping time with the electric fizzing of the loose wires; creating a macabre strobe-effect that intermittently illuminated the blood stained tiles. His whole body ached so much, he could not identify one single part that hurt more. There was no separate pain. Just a full, bodily, ache left by the live current in their attempts to shock the intel out of him. He had given them nothing, however. No matter how high the voltage went, he could not tell them what Sugar Horse was. He simply did not know.

The reel shut off as he awakened with a muffled scream, arms flailing against invisible captors and falling on thin air. His ghosts had gone, and it was almost dawn. Cautiously, he lowered himself down again, slowly lest he should put his back out on the floorboards and looked up at the ceiling. While he waited for the sun to rise fully, he lost himself in his thoughts. Sugar Horse: was it an operation? Or, a person? The person who sold him out, or some other lost soul languishing in the depths of a Russian prison cell?

He rolled over on one side, shifting his view from the ceiling to the skirting boards. They needed repainting, but first he needed to know who Sugar Horse was. He also needed to get up and start getting ready for work, but he needed to stay calm and think clearly. He could multi-task, though. He rolled over on to all fours and pulled himself to his feet. He bundled up the blankets and pillows and dumped them on the bare mattress before dressing himself. The act of functioning on a normal level reassured him of his own sanity. But the unanswered questions still lingered, still clawed their way into his conscious mind in defiance of the rising sun.

Breakfast done by eight, the doorbell rang at half past the hour. Ros waited on the doorstep. Impassive and impressive, she regarded him coolly through the small aperture as he forgot to unchain the door before opening up.

"Rough night," she said, eyebrow raised and arms folded neatly across her chest.

He couldn't tell whether it was a question or a statement.

By nine am, Ros and Lucas strode on to the Grid together. Her eyes scanned the room, clocking every person present, scouting for just one man while Lucas hung up their coats. She turned to watch him as he went, still skittish and nervy – as he had been all morning, since she picked him up. She had tried to bring up the subject of Mace and Cyprus, but he was lost to her, gazing into the middle distance. It was a stark contrast to just the previous day, when he had been chomping at the bit to prove himself.

When he returned to her, his clouded eyes searched hers for a full, unnerving, minute. She was about to raid her store of witty remarks to snap him out of his strange mood, before she noticed him turning to Harry through the glass front of his office. He brought his hand to his throat, as though she had just tried to throttle him. "Do you think he'll mind me going in there?" he asked, voice tremulous and distant.

Puzzled by her colleague's sudden need for approval, she replied: "Just remember to knock. He'll love you forever, if you just remember to knock."

She had meant it to lighten the mood, but Lucas sloped away as though he hadn't even heard her. She watched him walk straight into Harry's office, quite ignoring her jocular advice. Whatever desperate, angry admonishment Harry shot at the errant Lucas, Ros couldn't hear it. Instead, she opted to leave him to ride out his peculiar mood and go with her original plan as she guessed at the root cause of his problem.

She walked across the Grid, picking up her pace as Malcolm looked up from his computer and made eye contact with her. He dropped his gaze immediately, as if warding off a bad omen.

"Malcolm!" she chimed out to him, smiling brightly. "Guess what I have for you, today?"

Malcolm looked concerned. The worry lines around his eyes deepened as he inched away from her, as though he had somewhere to run and hide. "Oh, really," he said, failing to conjure any enthusiasm. "What's that then? Or, dare I even ask…"

She leaned in a little closer, over the top of the computer, and smiled a little wider. "I have all your birthdays and Christmas's rolled into one," she informed him, deadpan.

He made no reply. Ros quickly glanced over her shoulder, saw Lucas and Harry now sitting at the boss's desk and deep in conversation. They could be there all morning, so her coast was clear. She moved around the desk and sat beside Malcolm so they could speak without raising their voices.

"I trust you'll be discreet about this," said Ros, gesturing the reluctant Malcolm forward. "But Lucas is, shall we say, nervous about this Op in Cyprus. In case history repeats," she explained, careful to keep her voice down, even though only Connie and Jo were nearby. Jo was lost in paperwork, writing up reports. Connie's eyes were fixed on the screen in front of her, unmoving and not noticing anything happening around her. "I wonder, do you have anything to put his mind at ease?"

Malcolm finally began to relax. "I take it you don't mean herbal remedies?"

"Not quite what I had in mind, no," she replied. "We're going to need ways to communicate with the Grid anyway. But, I was thinking, maybe you had some tricks up your sleeve. Something for fast, reliable, safe ways for Lucas and I to stay in touch with the Grid at all times. Some way that messages, warnings or information can be passed without being traced or intercepted?"

Now, Malcolm's blue eyes twinkled before a whole world of espionage trickery opening up in his mind. He smiled the smile of a boy in a free-for-all sweet shop. But, before he could reply, Connie cut over them.

"Numbers Station," she said.

Ros jerked around to look at her, but she was still staring at the screen. For a moment, she thought the Analyst was talking to herself. She didn't even realise that Connie was listening.

"Of course!" Malcolm exclaimed. Ros could almost see the wattage of the light bulbs behind his eyes getting higher.

"Okay, but that's a bit old school isn't it?" she said, trying to keep his enthusiasm in check.

Malcolm rolled up his sleeves as he dived into an enthusiastic explanation. "Shortwave radio signals cannot be traced. Email, texts, phone calls … they can all be traced and tracked. Long wave radio signals can be tracked, too. The electronic messaging systems are also prone to outages and faults. But, like I said, short wave radio signals cannot be tracked and they never experience technical faults due to the nature of the signals. They're on air constantly."

It was a golden oldie of the espionage world and the more Ros thought about it, the more she found herself warming to the idea. "And there's hundreds of Numbers Stations already operating from all over the world," she said. "Most are fakes and hoaxes, so ours would simply be lost amongst them, if only we have the exact frequency."

"Exactly," Malcolm agreed. "We can play music on a loop to throw off the short wave radio enthusiasts, and only broadcast to you at pre-arranged times. Either Connie or I will read out the number sequences that make up the message, but the cypher needed to decrypt the sequence will be held only by Lucas, me, Connie and you. A numerology of all our own."

"Include the time of the next broadcast at the end of each message, vary it, and use strict call signs to give us some warning," Ros suggested. "But, how can we communicate with you?"

Connie came over to join them, bringing her chair with her. "Easy," she said. "We still have a bunker in Cyprus, just beyond the buffer zone. It's not on any map, obviously. It has a radio transmitter that is still fully functional. If you don't mind giving up your hotel rooms, you can take cover in there."

Ros's impossible dreams of five star luxury exploded into the infinity of her mind. But, she had dealt with worse than living in an old bunker from an age gone by. "That's perfect," she concluded. "But, Malcolm, if you have anything else…" her words trailed off, the rest of her sentence not needing to be voiced aloud.

Malcolm smiled reassuringly. "I'm sure I can think of something."

Connie got up to leave just as Lucas left Harry's office. His anxiousness had been replaced with despondency.

"When are you leaving?" asked Connie, just as she returned to her desk.

"First thing tomorrow morning," Ros replied, heading to the seat next to Lucas.

To her irritation, Connie followed her across the room. She stopped, just behind Lucas and started whispering in his ear, words Ros couldn't hear. But Lucas's reply to Connie's question was perplexing.

"Sugar Horse," he said. "Harry just thinks it was just a curveball question; he told me to forget about it."

It was clear from the tone of his voice, that Lucas was deeply unhappy at having evidently been dismissed. When Ros turned to get a proper look at them both, she saw Connie lay a gentle hand on Lucas's shoulder, her expression soft and kind – like she had been with Jo when she was upset over Adam. The Analysts inner granny was, once again, rising to the surface.

"I know how disappointed you must be, but Harry knows best," she said, now kind enough to raise her voice so Ros could over-hear. "If you remember anything else, or if there's anything else you need to talk about, my offer still stands. I like to think I can at least be more personable than hard-hearted Harry, there."

Lucas smiled, grateful for her offer – whatever it was. "Thanks, Connie. For everything."

Ros waited, grinning impishly, until Connie had returned to her desk. Then, she leaned to her left, until her shoulder touched Lucas's. "Aww!" she cooed. "Look who's got a new admirer already!" she teased.

Lucas tried to look disdainful, but the corner of his mouth kept twitching into a grin. "Don't be absurd!" he retorted. "She's been really kind to me since I got back. Unlike you."

Ros arranged her expression into one of impassiveness. "Oh, I have," she blandly corrected him. "It's just you have no frame of reference, and don't yet know how bad I can really be."

She jested the conversation to its close. But, it still struck her as odd. Connie had never been known for her people skills, yet had seemed to take a shine to Lucas. Ros glanced at the Analyst, but Connie was watching Harry. The Boss was on his feet and at the pods, throwing his coat over his shoulders as he marched off the Grid without so much as a by-your-leave.

For the last two miles of the journey to Nicosia, Ruth blocked her ears to the family squabble that had broken out between George and his sister and turned her face to the window of the coach. The sun-soaked landscape passed in a bronze blur; the rapid Greek of the row formed a buzz she didn't even try to keep up with. The child, Nico, lolled against her side, mercifully asleep, on the backseat of the coach and oblivious to whatever disagreement between mother and uncle had arisen. She lifted one arm and draped it around his narrow shoulder, keeping him steady against the rhythmic bumping of the coach.

An hour later, as they pulled into the coach station, an uneasy truce seemed to have been declared. Instead, Sofia turned her nervy gaze onto Ruth, with a sluggish Nico stirring from his slumbers under her arm.

"That's my son!" she snapped, her English heavily accented and, possibly, unintentionally abrupt.

Nevertheless, Ruth was taken aback by the tone. She looked from her, to her brother. George glowered at her behind her back, but said nothing. "I know that," she replied, giving the boy a nudge in the back towards his rook of a mother. She was swathed head to toe in black, more like a widow than a divorcee. "He fell asleep, I didn't want to wake him."

Sensing that any further discourse would only serve to heighten the row, Ruth got up and disembarked without another word, nor so much as a backward glance.

"I'm sorry about Sofia," said George as they managed to snatch a moment alone as they collected their luggage from the side compartment of the coach. "There's something I need to discuss with you, later."

Ruth watched him as he ducked under the sliding door to fetch their bags and heaved a sigh. "I'll hail a taxi, then," she said, at a loss for what else to do. Anything that eased their exit from this place was fine in her books, and a whole swarm of cabbies flocked amongst the tourists, touting for business everywhere.

As she went, Ruth found herself scouring the crowds as though she expected Mace to reveal himself from the midst at any moment. Of course, he did not. But being in the same city as him made her spine tingle with nerves. Only once they were safely booked into their hotel, under George's name, did she finally breathe easily.

After a cool shower to wash away the long journey from Polis, she thought about what she would do next. Her passport, under the name Emily Austen, was tucked away in her trunk. She would need it to hire a car and drive out to Mace's hotel and stake the place out from a safe distance. Before anything else, she needed the proof of her own eyes that Mace was still in the City. From there, it was a matter of working her way inside. But that was the next step after this one, a bridge she could only cross once she arrived at it.

Once out of the shower, she returned to the bedroom – a partitioned ante-chamber that led off from the main hotel room. It was light and airy throughout, a relief from the heat of the day that she was immensely grateful for. She looked around for George, but he was obviously still helping Sofia and Nico settle into their room, or having a rematch on that squabble. Either way, she used her time alone to gather the items she would be needing. Her mobile had a more than adequate camera function, but the zoom was hopelessly blurry. If she took a picture from a distance, it would be far too pixelated. Instead, she liberated George's digital camera from his suitcase and dropped it into her bag. She had rice paper, delicate and quick to burn if she should need to, folded into her handbag, along with a pen to mark down dates and times of sightings. She needed to build up a case, and do the best she could this far from the Grid and with no back-up team.

By the time she was fully dressed and ready to leave, there was still no sign of George. However, as she went to pen a short note to him, she heard the key in the lock. Seconds later, he stamped into the room, clearly still in a state of high exasperation with his sister. He flopped down on the bed, staring fixedly at the ceiling.

Ruth watched him for a second. "Er," she said, just to break the silence and alert him to her continued existence. "Everything alright?"

He sat up again, looking at like really had forgotten she was there. "Oh, yes," he said, clearly it wasn't alright. "Do you have time for that talk?"

Ruth was torn between her investigations and staying to ride out the family drama. But, she had come this far and she needed answers, lest they should all be placed in danger. Whatever crisis had arisen, it couldn't possibly be equal to the presence of Oliver Mace in their midst. She looked at him apologetically. "There's something I need to do," she said, reaching for her bag. She glanced at the clock to check the time. "It's only three, so I'll be back by evening. Is that okay?"

She had expected him to pry into her business, but he did not. He looked like he was going to press her to stay, but clearly had a change of heart. "Actually, that would be better," he said, falling back to the bed. "I need to calm down and think straight."

Ruth frowned, now genuinely concerned at what was happening. "Is it really that bad?" she asked, coming to sit beside him.

He twisted his head to look up at her and sighed deeply. "We'll work it out," he said, reaching up to give her thigh a squeeze. "Don't worry about anything. Go out and see the sights while I rest. I'll be here when you get back."

'Sight-seeing' was one word for what Ruth was doing, but that – like so many other things – was a subject for future discussion. Seeing that this arrangement suited them both, she leaned down to kiss him before sweeping up her back and heading out the door.

The hotel ran its own car rental service. Modest vehicles, but with tinted windows in a small effort to keep the interiors cool. Ruth noted it appreciatively, the tinting would shield her from outside attention, while blending in with the vast majority of other cars around. She signed her name "Emily Austen" on the form, grateful that George hadn't insisted on coming with her. Within minutes, she was out in the traffic flow. The hotel she needed was just beyond the border, on the Turkish side of the city. She showed her passport to the young Greek soldier who manned the checkpoints on this side of the city, and began the surreal journey through the two mile wide UN buffer zone.

Not far from where she was, the abandoned city of Famagusta lay deserted and slowly being reclaimed by nature. A ghost town that even the ghosts had probably deserted by now. Its car dealerships where stocked with vintage, 1974 models, all going to rust despite their value on the market. Houses and lives, stopped in mid-sentence and suspended animation. If she looked to her left, she could just make out the derelict hotels and decaying tower blocks and it sent a shiver down her spine.

Before long, however, she approached another checkpoint, this one manned by Turkish soldiers who once again glanced at her passport and waved her through. Driving through the buffer zone was like emerging from a tunnel, with life and the world reappearing in a sudden rush after a strange blankness in which there seemed to be nothing substantial. She now found herself surrounded by Turkish culture. A Mosque dominated the side street, and opposite it a busy market stall blared out loud, western pop music to a group of chattering teenage girls.

Ruth slowed the car down and jabbed the sat nav on, trusting it to get her to the hotel she sought. As it happened, it was hard to miss. Bedecked in Turkish flags, it was six storeys high and towering over the surrounding buildings. The imposing and elegant glass front was manned by two immaculately uniformed doormen. Ruth drove around the block, noticing that there were no side entrances, and the rear entry was inaccessible to her, reserved for delivery vans only. If she had still been with MI5, they could have sneaked her into one of those delivery vans, but it was futile thinking of what she could be doing. Instead, she turned her attention to what she was doing and parked in the street opposite the hotel, where she could see the front entrance clearly. All she had to do now was wait.

The passenger jet stuffed with excitable holiday makers, crying babies and air hostesses with painted on smiles, with two MI5 field operatives discreetly seated among them, began its ascent. Tail flaps opening, nose nudging the air current as it finally left the ground completely. Lucas gripped the armrest, turning his knuckles white. Ros glanced sidelong at him with a wry smile.

"You're not nervous, are you?" she asked.

"No!" he retorted, briefly glowering at her. "Bloody take off, and the damn landing. I'll be fine once I'm we're up there."

She raised her hand to the small window. "But look," she teased. "All the little matchstick houses and all the little matchstick people down there."

It was true. The view was unsurpassed. The whole of England seemed laid out before them. The Thames River a streak of blue ribbon dissecting London, even the tallest of skyscrapers appearing nothing more than a matchbox. Urban greys punctuated by green stretches of field; a peculiar patchwork of a nation only visible as a whole piece from above.

"I'm not scared!" Lucas protested again. "I just don't like this bit very much."

Ros rolled her eyes. "Yeah, right," she answered. "Anyway, it's got to be better than your last flight a few weeks ago. Weren't you gaffer-taped to the wing for that one, or something like that?"

Lucas grinned. "Yeah, just one strong bump of turbulence and I'd have been sucked right into the engine like a stray sparrow."

"What a sorry loss that would have been," she mused as she flipped open the inflight magazine, one she probably had no intention of actually reading. "Anyway, what were you in a sulk with Harry about yesterday?"

"Oh, nothing," he replied, breathing freely now that the plane had reached its full height. The pilot himself informed them that were cruising at thirty thousand feet.

"Didn't look like nothing."

Her eyes were still on the magazine, but she was clearly itching to know about the meeting he'd had with Harry.

"I told him something, about when I was in Russia and they were interrogating me about something," he explained. "And Harry dismissed it. Said it was probably just a curveball or nonsense."

Finally, she raised her eyes from the pages on the magazine. "Can you tell me more?"

"I was interrogated for weeks about something, or someone, called Sugar Horse," he said. "When I … remembered … it, I went straight to Harry. He just said: 'is that it?'"

Ros's expression softened as she looked over at him. "Lucas, you know Harry, he may sound gruff at times but he would never dismiss you out of hand. It sounds like he had genuinely never heard of it, or them. Can't say I have, either. Don't fret it; probably, they were just venting their Cold War hang ups on you."

Harry, Connie and now Ros had now told him to forget Sugar Horse. Each time someone said it, it seemed to become harder to do. He waited, looking at Ros to see if she had more to say on the matter, but she really had begun reading the inflight magazine, as if to emphasise the fact that the subject was closed. He suppressed the sigh on his lips and turned to the screen that mapped their progress. They were flying over France, by that time, getting further from London, further from Moscow and further from the truth.