A/N: My thanks, as ever, go to my readers and faithful reviewers. The Silly Season is well and truly upon us, but the Writing Must Go On, it seems, so here's a bonus chapter . There may be a few more of these to come over the next couple of weeks... Airgead ;)

Following the long stint of night duty I have just completed, Harry rosters me off for the next four days, and I am relieved to have a chance not only to address my sleep debt, but to stay at home, not interacting with anyone, or even leaving the house, unless I absolutely have to. I am exhausted, not just because of the demands of the job, which I have after all been used to for years; no, this feeling of lassitude and disinterest, of being haunted by unseen fears that lurk in the shadows of my life, comes from another cause altogether. I have my own black dog, albeit one that visits infrequently, but following the distress of my last encounter with Ruth, which has left me with the feeling that my world has twisted ever so slightly out of true, I find myself swamped by depression, the likes of which I haven't experienced in years. I turn off all my phones, disconnect from the Web, switch on the domestic perimeter security, with its CCTV and movement detection systems designed to alert me if anyone comes within a hundred yards of my property, and retreat into a self-imposed solitude. I need time to think, to sort through things in my own mind, and to give myself the breathing space I so sorely need at present; I stop consulting clocks, and sleep for days at a time.

On the third day, I am awoken from a restless snooze on the Chesterfield, by someone knocking persistently and impatiently at the front door. Befuddled and disoriented – the greyish light coming through the tall windows of the drawing room could be either dusk or dawn, I'm not sure which – and irritated that my security systems did not pick up the intruder, I stumble, wearing my pyjamas, to the front door, and peer, bleary-eyed, at the monitor installed there. Outside, a familiar face grins directly at the concealed camera in the roof of the portico, and the person the face belongs to raises one hand and waggles their fingers in greeting. A very familiar, bespectacled face. One that knows exactly where the camera is, because its owner helped me to install it, several years ago.

"Colin," I sigh, and reluctantly open the door; I am truly not in the mood for company, but I am unable to turn him away. The younger man comes in quickly, carrying a backpack with something spicy-smelling inside. "Blimey, it's cold out there tonight, it'd freeze the balls off a brass monkey! Here, I thought you might not have been eating very well, what with your Mum being away, so I picked up a curry on the way." Colin lopes past me, headed for the kitchen, turning on lights as he goes. Dazed, I follow him, noting that as usual, he has thrown his anorak carelessly over the suit of armour in the hall and kicked off his shoes, padding through the house in striped, mismatched socks, his sartorial signature, I remember him telling me once, from his school days. The shoe thing is a habit from his early upbringing; his mother had insisted that all outdoor shoes be left in the front entrance porch, so as not to clomp the dirt and mud of the city throughout her nice clean house.

By the time I walk into the kitchen, Colin has finished loading various foil containers into the warming oven of the Aga range (Mother refuses to have a microwave oven, despite my repeated and frequent reassurances that the wretched things are safe, and that she will not contract cancer from eating food prepared in one), and is stocking the fridge with some sort of beer. I'm not terribly fond of beer, generally, but will make an exception where Colin is concerned; he knows his stuff, and hunts out interesting varieties from the craft breweries that have sprung up all over Britain in the last few years. Closing the fridge door, he turns around and peers at me over his glasses. "God, you look rough. When was the last time you had a shave? Or a shower, for that matter?"

I draw myself up to my full height, aiming for a semblance of dignity (not easy to achieve when one is in one's night attire, granted) and retort huffily, "I had a shower this morning, thank you very much, and as for shaving, why should I bother when there's only me to see?" Colin continues to regard me with a mixture of exasperation and concern, before retrieving two beers – an India Pale Ale, appropriately enough. He pries the tops off with the opener he carries on his keyring, and hands me one with a wink. We chink bottles, and Colin hoists himself up onto the long kitchen bench, a manoeuvre of which Mother would definitely not approve. After a moment, I join him, feeling like a little boy again, climbing my grandfather's prized (and strictly off-limits) apple tree. We say nothing for a while, just sit companionably and drink our beer, until the kitchen is redolent with the exotic smells of chicken korma, lamb rogan josh, saag aloo, saffron pilau and naan bread. I make a note to air the kitchen thoroughly before Mother's return – she hates all 'nasty, smelly foreign food' with a passion. Mine had been a timid palate once too, until I arrived at Five and found myself eating whatever dubious takeaway the field staff saw fit to bring back to the observation van at outlandish hours. I do, however, draw the line at eating anything that comes in a bucket, or has the words 'Family' or 'Happy' in its name. One must maintain certain standards, after all…

While Colin extracts the bubbling, steaming containers from the oven, I set utensils on the bench: two bowls, two forks, a few serving spoons, and we busy ourselves with filling our bowls, before plonking ourselves, one a-piece, on the Chesterfields in the drawing room, and tucking in. I am surprised at how hungry I am, and when I go back for seconds, and then thirds, Colin asks, "Have you actually eaten anything since you left the Grid?" I stop to think, my third beer in hand. "Apart from toast and cereal, no, I don't think I have," I answer sheepishly. Colin frowns disapprovingly, and says, "I thought not, seeing as your mother's away and you have also apparently had some sort of falling out with Ruth." And there it is, the elephant in the room which had entered hard on Colin's striped heels. I look down into my bowl, suddenly finding the contents fascinating, but Colin is not to be put off by such a simple ruse. "How did you know?" I eventually enquire, dreading the answer.

"To start with, she's been hopeless the last few days, mislaying reports, forgetting to come to regular briefings, and she's even more vague than usual when she does turn up. She's not talking to anyone, not even Zaf, and she jumps when a phone rings. Add to that the fact that you went dark on all comms as soon as you left the Grid, and it doesn't take a genius such as myself long to work out what's going on." I know that Ruth is not Colin's favourite person, but this seems unduly harsh, even so, and I can't help myself: I rise to her defence. "Ruth's not vague, she's just a deep thinker, and I'll thank you not to say anything about her behind her back." Colin knocks back the rest of his beer, and eyes me in frustration. "I'll say it, if you'd rather, straight to her face…oh, that's right, I can't, because no one is meant to know. Honestly, when are the two of you going to come clean? Do you really still think that no one else has noticed? For God's sake, Malcolm, can't you tell me what's going on, and why you're both as miserable as sin?"

I set my bowl down carefully, stalling for time as I try to think of the right answer, but my mind is as clouded and grey as the sky outside, and I am so very tired of maintaining the increasingly absurd fiction that Ruth insists on. I realise that I need to talk, or risk spiralling further into the depths, despite what my father would say about keeping confidences. I have kept this secret religiously, and now it is making me sick. Locking onto Colin's solicitous gaze, I say quietly, "First, I'd like your word that this goes no further." He nods, eyes wide and serious behind his spectacles, and replies, "Of course, Malcolm. You don't even have to ask." And hesitantly at first, and then with the rush of relief that comes from setting a burden down, I tell him.

Not everything, of course; certainly not any of the more intimate details, and not about Toad Hall or the Tessina, but enough. At the end, Colin gives a long, low whistle, and taking off his glasses, he rubs his eyes tiredly. "No wonder you've been in a state, the last few weeks, what with thinking that she was pregnant. And you're not the only one who's been wondering what she's up to lately. There's a few of us who've noticed that she seems to be getting more…cosy…with Harry lately… and I haven't forgotten that she was a GCHQ mole when she first came, either. If you remember, you asked me to look into her transmissions, when Tom came to us with his suspicions." I nod, knuckling my own eyes, which are stinging with fatigue. "I love her, Colin, and I'd marry her if I thought she'd have me, but it's not that simple. Nothing to do with the Service is ever that simple." Not the Service, and certainly not where Harry Pearce is concerned, I add silently. We are both sprawled along our respective sofas, gazing into the flickering flames of the fire I had built earlier in the day, now burning low in the grate; Colin gets up, and returns with two more beers, handing me one despite my feeble protests. "This is a four-beer problem, I think," he quips, gleefully misquoting Sherlock Holmes, to my annoyance, before becoming thoughtful once more.

"The way I see it," he begins, after a long pause for reflection and refreshment, "is that while you know you love her, you're not at all sure that Ruth loves you. In fact, part of you suspects that she has romantic feelings for our esteemed leader, which is what I've been trying to tell you all along. And Harry certainly has been taking an active interest in her lately, for whatever reason. Then there's all that business with her being shuffled back to Cheltenham recently…I don't like it. Harry runs more agendas than any of us will ever know about and from where I'm standing, it looks like Ruth has started to feature more and more in his plans. I mean, if either of us approached him and said we'd fancy a bit of field work, thanks very much, he'd soon enough put us in our place, right?" I blink my agreement; words have become slippery and elusive, all of a sudden, and I am afraid if I speak now, they will tumble out in a jumble of things better left unsaid. Colin continues, "I don't know what to tell you, Malcolm. On the one hand, it's hard enough to find someone who understands the likes of us – and trust me, I know – but on the other, do you really want to be with someone who may, or may not, be in love with our boss?"

Colin's situation assessment is typically blunt, to the point, and searingly honest. I don't know that I am ready for this kind of truth, but at the same time I know that things cannot be allowed to go on as they have all year. It's time to apply some of my famed scientific objectivity and logic, for my head once more to rule my heart. With these ideas ricocheting around my brain, I open my mouth to agree, but what I hear myself say is, "I don't want to lose her, Colin. I can't…" The look on his face stops me short, as he replies in a tight voice, "I didn't want to lose Lucy, either, but in the end it wasn't up to me. That's the thing about a relationship, both people have got to be in it, boots and all, or the whole thing eventually comes apart." I look uncertainly at him, trying to see what he's getting at …something about boots falling apart?... With an impatient sigh, he clarifies, "Look, all I'm saying is, it's not just up to you. She's got to want it too. And for what it's worth, you deserve someone who's got both feet in the relationship. If you want my advice, you'll step back a bit, stop trying so hard, and then see what happens."

I nod hazily, and Colin shakes his head in rueful amusement. "You, my friend, are well and truly shipped." I get to my feet unsteadily; an empty beer bottle rolls away under the sofa as I tack towards the kitchen, intending to brew some coffee; somehow, though, I manage to come back with another two Pale Ales, and Colin laughs. "OK then, but I won't be driving home any time soon." I shrug. "No need to drive anywhere…I've got a bloody great houseful of spare rooms!" I tell him, as we chink bottles and I sink back down onto the sofa opposite him, wondering why his face is slightly out of focus. Must adjust the lens of that camera, I think muzzily, my best friend keeps fading in and out of view like the blessed Cheshire Cat…my best friend. Never thought I'd ever have one of those… "You're my best friend, Colin. Actually, you're the only best friend I've ever had," I say spontaneously, struggling with my s's, and he raises his half-empty bottle in salute. "Cheers! And you're not so bad yourself, mate." And then I remember no more, until I wake next morning on the sofa, a rug somehow draped over me and the empty bottles neatly lined up on the mantelpiece.

I warily crack open the other eye, and spot Colin, fast asleep on the other sofa, spectacles pushed up on the top of his head and his anorak covering his middle. Sitting up slowly, I stare at the bottles along the mantelpiece: eleven, twelve counting the one which I vaguely recall rolling under the Chesterfield. Did I really drink half of those, last night? I think I remember getting the fifth round, so Colin must have brought in the final two. No wonder I must have passed out on the sofa – Colin once referred to me, back in the early days of our friendship, as being a 'Cadbury's' drinker – a glass and a half and I was done for, and nothing much has changed, it would seem, in the intervening years. For men like Adam, or Danny, half a dozen beers would barely wet their whistles; for someone like me, unaccustomed to high-volume drinking, it feels catastrophic.

Groaning softly as I sit up, I head first for the downstairs lavatory, and then make my way gingerly into the kitchen. Coffee, I know, is the prescribed remedy, and food, something to help soak up the alcohol. Some elderly-looking sliced bread is all I can find, so toast will have to do. By the time the kettle is whistling and I have managed to feed four slices successfully into the old Dualit toaster, Colin is up, and he comes into the kitchen cheerfully. He looks a lot better than I feel, happily slapping butter and jam onto his toast, downing his second cup of coffee while I am still sipping my way through my first, and trying to remember where Mother's stash of prescription-strength ibuprofen is. "Don't you have to be at work?" I ask him, as he makes another batch of toast. "No, I had this booked as a rostered day off anyway, and Harry said it would be good for some of C Department's boffins to do a shift in our section, get them out of their labs and back into the real world."

I close my eyes in horror at the idea of C Department let loose on my systems, before consigning all such thoughts to the back of my mind. I am not due back on the Grid until tomorrow: sufficient unto the day the evil thereof. Colin continues, "Anyway, I'm happy to head out, and leave you to it, or hang about, if you'd like some company. I don't mind, either way." I am touched that Colin is prepared to give up a precious RDO to spend time with me; I am about to decline, politely, when it occurs to me that we haven't done anything together outside of work this year since our Doctor Who marathon, more than six months ago. Smiling at him, I swallow my mouthful of dry toast, and say, "I'd like that." Colin's eyes light up at my answer. "I was thinking we might work on some coding problems…I have them on my laptop, here." I squint, looking out the kitchen window, and smile at what I see: a pale blue sky, with wisps of cloud high up. "Perhaps we could go for a walk on the Heath, or head over to Alexandra Palace…look, it's going to be a beautiful day, once the fog burns off." And so it is.

I savour the crispness of the early October air, the crunch of leaves underfoot, the pleasure of being outside on a brisk and bright day, and the sheer enjoyment of spending it with someone who understands and accepts me as I am, with no questions asked, nor strings attached. For once, I do not even think of Ruth, as Colin and I talk about the things that interest us, and hardly anyone else of our acquaintance, while we ramble over the Heath. We walk as far as the old Duelling Ground, before heading for the Highgate Gatehouse pub, and partaking of a good and substantial lunch. I feel like a new man afterwards, invigorated by fresh air, exercise, food, and friendship. For most of this year, I have been so focused on trying to please Ruth and keep her interest, that I have forgotten what it was like to simply spend time with other people, and I am deeply grateful to Colin for reminding me.

We do not mention her again; enough has been said on that subject while in our cups last night; by tacit understanding, it is for me now to act, and for Colin to step back into the wings, like the good and trusted friend he is... amicus est tamquam, alter idem.

A/N: Malcolm is quoting from Cicero's treatise on friendship: A friend is, as it were, a second self.