I stare at the little yellow envelope icon that has just flashed up in the bottom right corner of my primary monitor with dread; it is from HR, and marked Urgent. I am tempted to delete it unread, but instead I hover the mouse over it and click, feeling progressively more anxious as I read:

Dear Mr Wynn-Jones

You are required to attend an appointment with Dr S. Chapman, CMO, at 0900 today.

Compliance is compulsory and takes precedence over all other orders.

Regards

Godfrey Bairstowe

Personnel Officer

Human Resources

I check my wristwatch: seven-fifteen a.m. Next, I save the email into my Personal folder, and peer over my screens to see who's in. Zaf is away, recuperating from the beating he took in Korsakov's penthouse; Adam is here, by the look of his workstation, but not in sight; Jo never arrives this early unless she's on an operation, and Ruth is sitting silently at her desk, with earbuds in place and a large pink post-it note which reads BUSY – PLEASE DO NOT DISTURB, stuck to the top of her monitor.

I know that she is working on the weekly threat assessment report, but I still can't help feeling that the message is meant for me alone. I have been back at work for two days, and Ruth has studiously avoided me. Even during yesterday's debriefing for Songbird, she had barely looked in my direction, or in anyone else's, for that matter, not even Harry's; and that, more than anything, had confirmed to me that she was indeed the leak. I wondered why Harry has done nothing about it; and then I had glimpsed his expression as he had stolen a glance at her during yesterday's briefing, and I had understood. He knows she is guilty of telling Adam, all right, but he has been compromised by the biggest double agent of them all: his own heart. Oddly, I had found myself empathising with him…for Guinevere held the hearts of both men in thrall…

The pods whir open, and as Harry hoves into view, Ruth removes the sign, and her earbuds, in one quick movement. I watch covertly as she tracks his progress across the floor, and when he is in earshot, she greets him with "Morning, Harry. Tea?" as she gets up in eager anticipation. Without breaking stride, he nods in her direction, "Ruth. Yes, for two." I see her eyes crinkle at the corners, as though she is smiling; and then Juliet Shaw appears, stepping out of the pods, and the pleased look becomes a pained one. "Black, no sugar," Juliet tells Ruth off-handedly as she strides after Harry, and for a moment I think that she might actually stick out her tongue at Juliet's impeccably tailored back, before her professional demeanour drops back into place and she goes off to the tea room to do his bidding. I, for one, wouldn't care to drink from Juliet's mug of tea, though – by the look I have just witnessed on Ruth's face, she would love nothing more than to spit in it, or add a few drops of something that will be highly disruptive to our dear National Security Coordinator's digestive system.

Fortunately, I keep the keys to the chemistry cupboard, as Colin calls our pharmacopeia of non-lethal compounds designed to cause instant illness, or sudden sleep, or even the appearance of death, in extreme circumstances, safely on my own person; I don't trust anyone else with them, except for Colin. And Colin is currently living it up in Barcelona, having plucked up the courage to ask Harry for three days off. He hadn't planned to leave London; but when he found a little windfall in his account, with the description "Performance Bonus" next to it, he had booked the trip immediately, and without any of his usual quibbling about how I shouldn't have, and he couldn't accept it. He must really need the break, and I'm pleased for him, even if I could do with his steadying presence, especially given Ruth's recent behaviour.

Ruth. I sit back from the long technical report I am writing on Korsakov's cage, and ways in which this technology could be adapted to our own purposes, and interlock my fingers before stretching upwards, feeling my ribcage lift as I push my palms towards the ceiling; it's meant to relieve pressure on the diaphragm, but my chest feels as tight as a drum and my heart as heavy as lead. Even my brain feels as slow and dull as a wet week, and I can't stop thinking in clichés. The silence which lies between us is oppressive, a tangible sadness that both of us instinctively shy away from. Ruth does not look happy; instead, she seems pale, withdrawn and ill, as she scuttles from her desk to the pods, or the briefing room, or Harry's office.

Seeing Ruth like this is very distressing, but a curious sort of lassitude has settled over me, and I'm so exhausted, it's all I can do to get to work, let alone summon the emotional energy to try and talk with her. It had begun on the drive back from Bournemouth, and by the time I got home, I could barely stay awake long enough to stumble upstairs and into bed. I had overslept yesterday, which is something I never do, and then I had made several basic coding errors while writing a security update for the latest Windows patch. My head feels foggy, as if I have a bad cold, and I can't maintain focus on anything for more than a few minutes… I realise that I am still sitting, arms stretched over my head, and Adam is speaking to me from the other side of the Grid. How he manages to come and go unnoticed is one of the mysteries of the ages, I tell myself, as I start in response to his question, "Hey Malcolm, are you all right?"

"Oh, yes, thank you. Just a bit…lost in thought. How are you, Adam?" Losing interest in my report, I stand up and walk towards him, as he gives me a smile that doesn't quite reach his eyes. "Me? I'm all right, as far as it goes. Still…adjusting, I suppose." I nod awkwardly, unsure about what to say next. I spot a photo of Adam's little boy, Wes, on the desk next to his telephone, looking very much as Adam must have done at that age, and yet I can see his mother in him too; the blonde hair is Adam's, but the shape of his face is all Fiona. Adam, always watchful, follows my gaze. "It's hard on him, he really misses his mum." I nod again; why do words always seem so clumsy, at times like this? "I should imagine so: Fiona was devoted to him, and to you. I'm so sorry, Adam. I know you must be sick of hearing it, but I really am." He nods his thanks as he quickly swivels his chair away from me, but not before I catch the sheen of unshed tears. Abruptly, he scrubs his sleeve across his eyes, and I turn away, wanting only to give him privacy. I catch sight of the time on Adam's oversized chronometer as I do, and am surprised to see that it is already eight a.m. An hour to go…

I sit back down at my desk, trying not to think why the doctor might want to see me again. I don't succeed. Just as I have convinced myself of the very worst possible scenario, Jo arrives, bringing breakfast with her. No-one else I know can eat hot chips at this time of day, and my nose twitches at the savoury scent: with Mother away, and in my strangely uncaring state, I am becoming lax about eating regularly, and twice now have left the house without breakfast. I look up to see her standing in front of me, and she grins as she sets a brown paper bag on my desk. "Morning! Didn't think you'd have eaten yet," she greets me happily, and I open the bag to find a not-quite-hot cappuccino, and a couple of rounds of toast with Marmite, from Jo's favourite café on the South Bank. "Thank you, Jo, what a kind thought," I reply, smiling properly for what seems like the first time in days, as I pull out my wallet from the breast pocket of my suit, intending to give her some money. As I do, a little gold USB falls out at the same time: the GCHQ security swipe records, which I had forgotten were still in my jacket, and which I haven't yet had a chance to review. "Oh, no, please don't worry about it," Jo assures me, waving away the proffered note, "You can buy me a coffee sometime." She makes her way towards her desk near Adam, and pauses as she passes Zaf's chair, still with his favourite leather jacket hanging from its back: her fingers brush over it, and in that tiny gesture, all her unspoken feelings are expressed.

"He'll be back before you know it," I say encouragingly as she sits down and begins to log on. "He's as tough as they come," I add with considerably more conviction than I feel, as I embark on my second round of toast. "I went to see him the other night," Jo volunteers, "He's bored out of his head in hospital. He asked for some DVDs, but all they have are a few Disney movies in the children's ward. He didn't think it was funny when I suggested he join them." Her comment about hospital reminds me of Hugo Ross, and I ask what his prognosis is. Adam looks over at that and shakes his head. "What prognosis? The antidote wasn't effective long-term, no wonder really, seeing as it was a prototype that had sat around in a fridge at Porton Down since before the Berlin Wall came down. Ross won't be going to France; he doesn't even know that France exists anymore." I wince at the idea of this brilliant and brave man, all his talent and knowledge lost forever, spending the rest of his life in another kind of prison. "And how's Harry…" I begin, only to nearly jump out of my skin when a deep voice says right in my ear, "Badly. He's taking it very badly."

Once my heart has resumed its regular rhythm, I swivel around to face Harry, who is grinning wolfishly at the effect he has created. Of necessity, my immediate attention is divided between noting that the peculiarly unpleasant, damp sensation in my lap is the result of spilling half my coffee when Harry made his presence known, and wondering what it is that he wants. Just as I feel certain that my humiliation is complete, I notice both Ruth and Juliet, peering at me from a short distance behind Harry's back. "Would you be so good as to join us in the briefing room, and share the fruits of your wisdom in relation to that cage cracking thingy?" I get up gingerly, glancing at my watch: eight thirty five a.m. "Of course, but I'm afraid I can only give you fifteen minutes. I have an appointment with the CMO shortly." Harry watches me impatiently as I mop at my trousers with my handkerchief, before saying drily, "Fifteen minutes of technobabble? I think I'd rather join Hugo Ross in unhappy oblivion, thank you. Make it five at the most." Happy to oblige, I think sourly, as I follow them back to the inner sanctum. At eight-fifty a.m. I excuse myself, having delivered an uncharacteristically rambling and disjointed explanation of the Faraday cage and Colin's spike program, and trot nervously towards the lifts. That was an appalling presentation; I just can't seem to get my head together…

The state of my head is what Dr. Chapman is interested in today, as it turns out. I take a seat in her office at 0900 precisely, and she hands me a page of lab results. "Malcolm. Thanks for coming back to see me. These are your bloodwork results, and this" – she slides another page over – "is the STI panel. All clear, I'm sure you'll be relieved to know." Blushing, I look over the results as she speaks, but the numbers are meaningless, in my current state of mind. Dr Chapman leans forward slightly, and adds, "I do have some serious concerns, though. Your cortisol levels are as high as any I've ever seen, your insulin is up, and you've got as much epinephrine in your system as a field officer coming off a dangerous op."

There is an oddly gentle edge to her voice, as if she is breaking bad news; slowly, I meet her gaze, and my heart skips a beat for the second time this morning as she continues talking. Her cornflower blue eyes are full of empathy as she speaks, her elegant hands move gracefully as she emphasises her points, her wavy red hair is held loosely in a golden clip at the nape of her neck, and for all I know, she could be wearing the most exquisite gown, or absolutely nothing. I am completely transfixed, not just by the good doctor's very considerable personal charms, but by the words I think I have just heard her say: leave Section D?

"I b…beg your p…pardon?" I stammer in shock, and she frowns, perplexed at my response. "It's nothing to worry about, people do it all the time. I've already started the paperwork for you." I don't understand; am I being summarily discharged on medical grounds, and if so why hasn't Harry said anything? "Malcolm? What's wrong?" I gasp for breath, wondering how such a simple task can suddenly become so laborious. Dr Chapman's face seems very far away, and very close to mine, at the same time; and why is the room spinning, and why do I feel so cold, when I'm sweating like a racehorse? There's something wrong with the lights, too… they're flickering on and off, off and on and…

As I come round, I am simultaneously aware of three things: oddly, my knees are next to my ears, there is a firm, cool hand on the back of my neck, and Dr Chapman herself is crouched before me, regarding me with a judicial eye. "Oh good, you're back. Don't sit up just yet, or you could faint again. Here's your inhaler: take two good puffs, please. You went out like a light." Her voice is strictly professional, and yet there is an undertone of warmth, and something else too: amusement, or perhaps exasperation… "W…what happened?" I ask, after I have obeyed orders as directed. There doesn't seem to be much else to ask…I feel utterly ridiculous, sitting here with my head between my knees…ooh, I feel all woozy. I think I'll just do as she says…

"You don't remember? You didn't lose consciousness that fast…it was more of a gentle forward slump, really," she tells me as she flicks a penlight beam in first my right, then my left, eye. I slowly sit up, ignoring her steadying hand; she removes it as I confess, "I don't remember what you were saying before because, to my eternal shame, I wasn't listening. Not properly. I've had rather a lot on my mind lately, I'm afraid…but, but nothing I can't handle, no more than the usual…" Dr Chapman stares, her expression incredulous, before she decides to humour me.

Settling back in her chair, she crosses her long legs, neatly clad in grey flannel trousers, and says, "I was saying that in my opinion, you were showing all the signs of long-term exposure to severe stress, and I felt that a change of scene would do you good, somewhere away from Section D. There's an STO in C Department looking for a replacement while she goes on long service leave. The other option is to force you to take some of the frankly silly amount of annual leave you've accrued over the years, but I thought you'd rather leave Section D for a development opportunity; it just looks better, and you know how people talk around here." Unfortunately, yes, and I can already imagine the speculation and rumours that would circulate if I were to take a large chunk of unscheduled leave…

She smiles at me encouragingly, but I don't know what to say, or where to begin. I feel such a fool for fainting, and I haven't ever really considered working anywhere else in the Service: Section D is my home. And yet, the evidence is irrefutable: she has the test results, and now my sudden swoon, to prove it. I hadn't really considered it before, having simply borne it all like an overloaded, but still willing, beast of burden: months of worrying about Mother's bizarre behaviour, my gnawing anxiety over the state of my relationship with Ruth, not to mention Harry's strange attitude of late, and finally the nearly overwhelming distress and frustration I had felt when I had been unable to crack the wretched Faraday cage. Then, there was that strange encounter with the old churchwarden at Bournemouth, which I have almost chalked up to Aunt Emily's brandy… perhaps I am stressed, and a change would do me good. And C Department, not to put too fine a point on it, would suit me to a T: I would be practising pure science for a change, instead of the rather rough-and-ready approach that field operations so often demand. I have a brief vision of myself in one of their stark, white cleanrooms, alone with their mainframe…it is a very alluring thought. All that peace and space, and not another person in sight…

Still feeling muzzy, I want to make certain that I understand her. "So, you didn't mean that I should leave altogether then? That is a relief! Obviously, I misunderstood… I thought you were going to invalid me out of the Service. I'm sorry if I alarmed you, earlier; I've never had a turn like that before." Dr Chapman says nothing, just sits and waits for me to continue, and for an instant, I consider what a relief it would be to take her into my confidence, and tell her everything. I know I can't, though: loose lips sink ships, as the old wartime slogan went, and careers and relationships, too, I have observed all too often in this strange life we lead. And I am very well aware that 'stress' is the Service's catch all diagnosis for everything from "we suspect the officer might be experiencing a momentary lapse in mental hygiene" to "we're fairly certain that the officer has gone right round the bend" (or 'Harpic', for short), to "we now know that the officer is totally loopy and must be stopped by any means possible". Just hearing the word makes me shudder: I know that 'stress' is in fact the most common reason to decommission officers, and I can't help but think of Tom Quinn's ignoble departure.

Eventually, I am unable to bear the doctor's silent scrutiny any longer, and add, "You must think me the most colossal fool; I'm a positive disgrace to the best traditions of the Service." My intention is to try and make light of what has been an exquisitely embarrassing experience, but Dr Chapman's eyes darken as I speak, and I fear that I may have unintentionally said too much. She clears her throat, and says evenly, "Oh, I wouldn't say that. I would say that you have confirmed my initial assessment in a fairly spectacular fashion, though. Malcolm, I see all the damage that the Service can inflict on its own people, and usually I see it too late to be able to do anything other than try to pick up the pieces. Well, not this time. I'll speak with your section chief today." Oh, no, not Harry… My panic must show on my face, for she changes tack smoothly. "Or we can do it through back office channels, have a secondment order issued by HR. Whichever you're more comfortable with, if you're interested, that is?"

I open my mouth to tell her No, thank-you, I'm perfectly happy where I am, but instead I hear myself say, to my very great surprise, "When would I start?" Dr Chapman smiles, and reaches for her prescription pad. "As soon as possible, I believe. She goes away next week, and there would need to be a handover, of course." She scribbles something, tears the page out and hands it to me. I glance at it and look up at her in surprise. "What's this?" Her smile widens a fraction. "My private number. In case you should ever feel like a chat - completely confidential, of course - sometime. And no, I don't hand it out to just anyone." She turns back to her computer screen, adding briskly, "Thanks for coming in. I've got to go and vet the DG now, so if there's nothing else..."

Automatically, I get to my feet, tucking the small slip of paper into my breast pocket, alongside the little gold USB. Half a dozen different interpretations of this unexpected, and as far as I know, unprecedented, offer from the Chief Medical Officer tumble through my stunned brain, each more alarming than the next; I feel my face reddening at some of my wilder suppositions, but I have to know. "Erm, Dr Chapman?" I begin hesitantly, "Why are you doing this, offering to help me, that is?" She gets up, and pulls her doctor's bag out from beneath her desk, preparatory to leaving. Standing, she's nearly as tall as I am, and her startling, almost purple eyes glint with an expression I can't quite identify. "Let's just say I like to be proactive in my practice of medicine, every now and then. I really do have to go, now. Come on, and we'll get the lift together. By the way, I see your skin's healed," she notes, gesturing towards my ringless left hand as she strides to the door.

We travel up from the lower floors in silence, until I reach my floor; as I step out of the lift she says, almost too low for me to hear, "And because everyone needs help, every now and then, but too few in this job ever ask for it…I'm help, Malcolm." Before I can turn, or reply, the reinforced steel doors slide shut and she continues on, to the exalted heights of the Executive floor. I feel the tiniest bit lighter, somehow, as if I can finally see daybreak at the distant end of a long, dark tunnel I have been stumbling around in, and it is with a decidedly more cheerful step that I return to the Grid.

I commence my secondment five days later, with Harry's blessing.