A/N: I know, I know. It's been a long while between updates. RL is speeding up, not slowing down as I had hoped, but in between the madness, I have been working away on this chapter, which has not been the easiest to write, given everything that's going on in 5.1/5.2. Confession time: I have also started a story for Silk, the BBC legal drama, and posted the first chapter a few days ago. I did promise no more side projects until H, L, & S was complete, but when inspiration strikes, it's very hard to ignore! And in my defence, with this update, the story passes the 300,000 word mark. To put it another way, the average published novel length is about 95,000 words, so if I occasionally feel the need to write something else and play with other characters in other worlds, is it any wonder? Thank you all for waiting so patiently, and reviewing so enthusiastically. You're the best!

Abiit nemine salutare…

Dr Chapman, it would seem, is a woman of rare patience; when the weeping becomes shuddery sobs, and then subsides into shaky breaths as I try to regain some sense of equilibrium, she is still sitting next to me, waiting. I gulp for air as I fight against the encroaching tightness in my chest and try to control the trembling of my limbs. She is still sitting next to me, waiting, when I finally lift my head to look at her through red-rimmed eyes, wondering why she is here: surely she has more important things to attend to? Apparently not, for she meets my look with a searching gaze of her own. "Tell me," she invites gently, and for a heartbeat, I am sorely tempted to unburden my soul. It would be such a relief…and yet, I know that I can't, not now, in the middle of the most alarming events that Britain has seen since the worst excesses of the IRA in the Thatcher years. It would be an act of supreme self-indulgence, and besides, the more I think about it, the more I realise that I don't want to talk about what's happened to my best friend: instead, for the first time in my life, I truly understand what it means to hate.

For I hate them, these men who have taken Colin from all those who loved him, with an intensity like nothing else I have ever known, except perhaps the feeling of finishing hard with Ruth raking my back and digging her heels into my buttocks as she spurs me on to that moment of suspended animation when I know that the delightful inevitable is about to occur, overwhelming my body and my mind with pure physical sensation…except that this, this is as different as night from day. Just as powerful, but in it there is no joy, no release, just an endless upswelling of rage and darkness and a need to retaliate so strong, I can taste it, like the metallic tang of blood in my mouth when I bite my tongue…too late, I realise that I am doing just that, my jaw clenched tight with rage. Dr Chapman is watching me closely, and I realise that I haven't said anything to her beyond those three dreadful words. With a great effort, I loosen my jaw, feeling the tightness in my neck beginning to reach into my trapezius muscles, and settle into my rhomboids with a vengeance. I welcome it, welcome the pain, for it reminds me that I am alive, unlike poor bloody Colin.

"I can't." My voice is as creaky as a rusty door hinge, my throat dry as I repeat, "I can't. Not now. I have to work, to find the bastards that killed him…because of them, this country is standing on the brink of the precipice, and I'm not at all sure that we can pull it back in time. So you'll forgive me if I decline your kind offer to bare my soul." The doctor gets up gracefully, almost certainly offended by my brusque refusal of her help; I am sure of it, until I see her hand extended towards mine. Humbled, I take it, and she steadies me as I stiffly climb to my feet. Once we are both upright, she doesn't let go of my hand immediately. "I'm going to certify you as fit for duty, but the caveat is that you talk to me, or Diana Jewell, once all this is over. Do I make myself clear?" Her eyes hold mine steadily, and I find myself reluctantly replying, "Yes, all right." She lets go of my hand then, and steps back, allowing me to pass. As I cross the freshly-mopped threshold of the briefing room, she speaks my name in a low voice, and I turn back to hear her say, "Whatever you might think, you're not alone. There are people who care about you; let them help, for God's sake."

I attempt a brief smile in acknowledgment of her kindly meant words, but it is a sad and sorry thing, not even reaching the corners of my mouth, much less my eyes. I will never smile again, I tell myself as I walk down the corridor towards the Grid where Colin isn't, and will never be again, or laugh, or make love to a beautiful woman, or indeed, any woman…all joy has gone from my life now, along with the best friend I will ever have. Just as this thought occurs to me, I see Colin's MP3 player still sitting on his desk, and I surreptitiously unplug it and slip it into the inside breast pocket of my suit in passing. I can't explain it, other than that it's a tiny piece of him, and I don't want anyone else to touch it. With its comforting presence a small weight against my heart, I take a few deep, steadying breaths, and look about the Grid to see what's happening. I can't believe that only half an hour has passed since Harry stepped into the briefing room with his news; it feels as if time itself has stopped. Nothing will ever be the same…oh, Colin. Why did you ever agree to go out in the field today? Adam should never have asked you; he had no right. Your death is on him, and Harry, and this whole damnable organisation that survives by chewing up the brightest and best and spitting them out in the name of the Service…

Checking my email, I see an urgent meeting request from Ruth to all of Section D; my eye is drawn instantly to Colin's name in the distribution list, and a great wave of anger towards Ruth for her thoughtlessness rises up, until I see that the meeting is now, and I hasten towards Harry's office. When I arrive, there is nowhere to sit: Harry is in his usual place, with Ruth in one of the visitor chairs, and Adam the other. Jo, who must have been red-flashed to come in from the field, is perched on the arm of Adam's chair, and Zaf is leaning against Harry's desk. All eyes turn to me as I arrange myself awkwardly in the doorway; I glimpse sadness in Jo's gaze, and immediately look down at the floor, afraid that if any of them shows me even the most basic of human kindnesses, it will be the undoing of my fragile composure.

As it turns out, I have nothing to fear: Colin is not mentioned at all during the brief, which focuses on Jo's work with Rowan. She is worried that she will not be able to guard him indefinitely on her own, and she has recently begun to suspect that he may be developing romantic feelings for her, which adds an additional layer of difficulty. Adam counsels her to allow it, for it will make him easier to manage, as long as it doesn't get out of control. "He's only twenty, Jo, and he's a nice kid, you should be able to handle it." Jo is only a few years older herself, and can easily pass for nineteen or twenty, especially when she is dressed like the university student she is claiming to be. I can just imagine the effect that she would have on a sheltered, sensitive boy like Rowan, just out of an exclusive boys' school in the Berkshire countryside; she would be nothing short of dazzling, and I feel a twinge of sympathy for the Prime Minister's son in spite of everything that I am trying not to feel on my own behalf.

As the briefing concludes, I am the first to leave, unable to watch as Ruth slips smilingly around to Harry's side of the desk to look at something over his shoulder, and unwilling to expose myself to the clumsy condolences of my colleagues; Jo catches me, though, in the corridor. "Please, Malcolm, wait," she begs, and slowly I stop and turn around to face her; she steps in close, and gently lays one hand along my cheek, while her eyes, shimmering with tears that threaten to spill over at any moment, meet mine; there is no need for words. I raise my own hand to cover hers, deeply moved by this simple gesture of shared sorrow, and after a moment I whisper, "Thank you." She whispers back, "Any time, and I'm so sorry about Colin," and then we hear the sound of the others coming out of Harry's office, and break apart before we are seen. As Jo strides off along the hallway, en route to the car pool, Dr Chapman's words come back to me. There are people who care about you; let them help, for God's sake. So it would seem…and then Ruth passes me without so much as a look, or a word, too deeply engaged in conversation with Adam to talk to me, and I wish that the reinforced concrete floor under my feet would open up and swallow me whole.

They seem to be discussing his domestic arrangements – I hear the words Wes, interview and nanny as they pass by – and I wonder why Ruth has decided to appoint herself as Adam's major domo and chief caretaker: she has insisted several times since his return that he should leave early or slow down and take things easy, much to his thinly-veiled annoyance. It's as if she is appropriating Harry's authority as her own, under the aegis of her role as senior intelligence analyst, acting as if they were one and the same: but I have seen this happen before, staff mistaking Harry's trust in their operational abilities for something else, something closer, and it never ends well, for Harry Pearce does not willingly cede so much as an iota of his power to anyone. He's far too wily for that. Juliet Shaw openly refers to Ruth as 'Harry's spaniel' with amused contempt, but I disagree: she's more of a sheepdog, to my mind.

A sheepdog is loyal to only one master as they work together to control the flock, but the one thing a sheepdog must never do is exceed its own powers: a sheepdog that takes it into its head to act independently of its master is a sheepdog living on borrowed time. And while it obviously suits Harry to have Ruth running about after Adam, barking at him so he doesn't have to, she had best make sure she doesn't overreach her limits, or one or the other will put her back in her place so fast she won't know what's hit her. Connie James, Tessa Phillips, even Zoe: I have seen it all before. What none of them seem to realise is that Harry is a master manipulator, so skilful that he can have them wrapped around his little finger, doing his bidding, and believing all the while that they hold sway over him, that they share a special relationship with him, that he needs them. And he lets them, until it no longer suits him: sheepdogs that are disobedient, or that harm the herd, or that simply go their own way, are not tolerated. Ruth, how little you know of the man you would have for your own, or of the things he has done, and the people he has done them to…

I trudge towards the server room, seeking the solace of solitude and quiet, cool spaces, but it is unbearable: everywhere I Iook I see Colin, standing by the server racks, or hunched over at our makeshift desk, working on his latest gadget, or concentrating on the system diagnostics flickering down the screen in an endless stream of machine code. The very air, still and chilled, reminds me of a morgue…shivering, I return to the Grid, and try to focus on something, anything to keep my mind occupied. No one looks in my direction, or speaks to me, and I know why: I am tainted by death, and in the best traditions of the Service, they are all doing their damnedest to stay away lest its shadow fall on them. I know that once the operation is over (if it is ever over, and the world order remains the same, my newly cynical self adds) Colin's desk will be cleared out, a mountain of paperwork will be completed, a date for his memorial service will be set, and all the right things said; a few rounds of drinks will be bought afterwards, and then he will never be mentioned again. Well, not this time, I promise myself, and them, grimly. Not this time. I will not allow my friend and colleague of seven years and more operations than I can count simply be forgotten as we rush on to the next crisis. I will not. I will find whoever did this, and hold them to account. I will have my pound of flesh, torn from each of their black hearts… I begin to understand how powerful the desire for vengeance is, and how seductive an emotion hate can be, as strong as love and twice as destructive.

Staring at my monitors, I process incoming intel, updates, and requests for field gear without really looking at any of it, while I fantasise about how Colin's killers should be served, once caught. Hanging, drawing, and quartering is too good for them, if not for those executed for high treason… perhaps injecting them with flesh-eating bacteria, or Ricin…no, not slow enough…maybe flaying the skin off them, bit by bit, and then letting loose a colony of fire ants…I am sickening myself, but I can't seem to stop, for the spectre of Colin hanging from a tree at Runnymede is constantly before me. I almost jump out of my own skin when Adam's hand descends on my shoulder. "Sorry, I did try speaking to you first, but you were miles away. There's a briefing at my place in an hour; I think we need to get off the Grid, after what happened to…to Colin," he wavers as I stare at him silently. "And I've got Wes to get to bed," he adds lamely, as I shrug his hand away and nod once, curtly. "I'll be there," I tell him as he turns away, obviously relieved to be escaping my presence. I sense that Fiona's death is still very much at the forefront of his mind, a raw wound that goes deeper than any of the physical damage he sustained from Miss Wells' bullet; there are those who mourn best with others, and there are those who need to grieve alone, and we are both of the latter persuasion, each of us wanting only to be left in peace to mark our loss in our own way. But even knowing all this, I can't help but wish he had said something to acknowledge the pain I am in, given that he too must be suffering from the death of a man he had sent into the field. Doesn't anyone in this job have even the slightest sense of remorse, I wonder as I power down my array, and cross to power down Colin's, still running from when he logged in this morning, or the merest scrap of human decency, when confronted with the murder of an innocent man, and a colleague to boot?

By the time I arrive at Adam's Docklands flat, I am in the blackest of moods, and the situation is not improved when I survey the sitting room; I am the last to arrive, for Zaf is already seated on a long, low settee. Harry is beside him, with one arm draped casually along the back of the settee, reaching out for Ruth, who is leaning towards him and looking as pleased as Punch. Adam shows me to an armchair at right angles to the sofa, and fetches me a drink – whisky of some sort, which I studiously ignore – before excusing himself to attend to Wes. Complete silence descends on the room for several minutes, during which Harry drains his drink, Ruth plays nervously with her hair, and Zaf looks as though he would rather be in the midst of an Al-Qaeda cell than here in this large, pleasant room overlooking the Thames. When the silence becomes too much, he is the first to crack.

"So, who was that icy blonde with Adam on the Grid the other day?" he asks no-one in particular, and Harry replies, "That's Ros Meyers from Six. She's acting as their liaison during this…unfortunate situation… in which we currently find ourselves mired. Her father is Sir Jocelyn Meyers, chairman of Gastream, leading City man and philanthropist. High flyers, both. She's just come back from Baghdad, where she took down a nest of informers single-handedly, or so I believe." Ruth giggles unexpectedly, and I see that her glass is empty. Judging by the way that Adam pours his whisky, she must have had at least a double, if not a triple. "Meyers…mired…that's quite funny, really!" she adds, her voice husky from the spirits she has consumed, and Harry shifts his bulk an inch or so closer. I know the effect of strong drink on Ruth all too well: it makes her amorous, to put it mildly, and as I watch in disbelief, she daringly brushes her foot against Harry's shin, a tiny movement, but one that none of us miss. Zaf coughs, reminding them they are not, in fact, alone, and she draws back as though from a naked flame. I glance at Harry, and immediately feel sick at the speculative look in those glowing amber eyes: he is wondering how much more whisky it would take to get her into bed tonight, if I'm not very much mistaken, and the gross indecency of it all, coming on top of Colin's murder, seals my enmity towards them both.

In an attempt to control both my revulsion and my grief, I am sitting stiffly in the too-soft chair, my hands clamped onto my knees in the classic brace position as I struggle to retain some semblance of dignity and control (unlike others, I note bitterly) in the face of my colleagues, my ex-lover, and my boss. I have never missed Colin's calm, pragmatic presence so much as in those few seconds, when all I want to see is his familiar face looking back at me from the armchair opposite, covertly rolling his eyes at the pair on the sofa, his long fingers tapping out a message in one of the dozen or more codes we routinely use with each other for moments such as this. Hang in there, mate, he would have told me, or perhaps, Why don't they just get a room?

Instead, there is only an empty chair, and all the loss and loneliness in the world, as the unthinkable occurs to me: I will never, ever, see my best friend again. He will never come loping through the pods, bicycle clips still in place, or slip out, far too late from the back of the server room. I will never again give him a lift home from an all-night shift, or open the back of the surveillance van to find him hunched over a bank of monitors as he listens intently to the audio feed from a bug he has not only placed, but built to his own design…and I will never see his eyes light up as we pore over a new bit of technology, or decipher an obscure code; never hear his voice again, quoting the Hitchhiker's Guide from memory as we sit, bored almost to tears, on an uneventful obbo… "Here I am, brain the size of a planet, and they ask me to take you down to the bridge. Call that job satisfaction? 'Cos I don't." Oh, Colin

When Adam comes back into the room, I speak for the first time since arriving, unable to contain myself any longer. "I don't understand. How could somebody do that, to Colin?" My voice sounds flat and dull to my ears, and Ruth, who knows every inflection, every cadence, every nuance of my speech, looks up, alarmed. Eventually, Adam responds to my question, once it is clear that no-one else is going to. "Nobody would have dared do this without high level authorisation; they're telling us they stop at nothing." Puzzled, Zaf frowns, "We keep talking about they. Who's 'they'?" Adam and Harry exchange glances, before Adam answers, "We believe there's a conspiracy underway, which is using the terrorist onslaught as a cover for an attack on the government. So, Michael Collingwood, certainly. Perhaps Millington has been putting his press at their disposal."

Well, that would make sense: David Millington is a Fleet Street baron who publishes some of the most right-wing redtops, the tabloid papers that cater to the lowest common denominator in society. And if such a view makes me a snob, I'll wear the label with pride, and flee back to the civilised world of The Times, or at a pinch, the Telegraph, neither of which see the need to adorn page three with scantily clad females or fill their columns with gossip about footballers' wives… Harry weighs in, his voice strangely out of place in this cosy domestic setting, while Ruth watches him demurely from beneath her lashes. "They ignored intelligence about terror attacks, spread the panic, and took out the Prime Minister's closest ally who was about to secure a deal on an important Bill regarding homeland security." Adam adds tightly, "And now they've killed one of us." Ruth looks away, and she and Harry draw apart slightly on the sofa as I glance in their direction. I can't stand it: Colin is not even six hours dead, and they're flirting like teenagers. Disgusted, I decide to place the focus back where it belongs.

"You know the last thing he did? It was an MP3 for Jo. It was very clever, it's got a tiny transmitter linked to the alarm system warning her of an intruder. If she's asleep, it sends a signal to her wristwatch, making it vibrate. Simple but smart. That's how he does things." I look around the room, daring my colleagues to contradict me, but no-one does. Adam advises, "From now on, only routine business on the Grid. Everyone needs to check their personal security, and Zaf, you must warn Jo immediately." He means, of course, that the Grid is no longer safe, and for Jo to begin following doghouse protocols and contact methods, rather than thinking of Thames House as her home base. Harry also ignores my bid to bring Colin into the conversation as he observes, "They want us to know how confident they are." Ruth asks Adam, "What are we going to do now?" and he replies, "There's not much we can do, at the moment…"I can't believe what I'm hearing, or rather, what I'm not hearing, and I bitterly cut across him with, "Because he wasn't important enough." How can they be so callous, these long-term colleagues and so-called friends of mine? Zaf speculates, "We could take out one of theirs in return, but what would that get us?" My response is immediate and visceral; I spit out, "Satisfaction!" and do not recognise my own voice. Ruth is looking ever more concerned, but Harry, barely turning in my direction, simply intones unctuously, " Our satisfaction will come from defeating their conspiracy," and something in me snaps, anger rising like a red tide behind my eyes as I shout, "Oh, shut up, you pompous old fool! He wasn't just some geek who did crossword puzzles, he was my bloody best friend!" Startled, Ruth's eyes turn first to me, and then back to Harry, while her body language couldn't be clearer: she has chosen her side and she's sticking to it. I am utterly alone…no-one else understands how I feel, because no-one else feels the same way.

Adam gets out of his chair, comes towards me, sits on the edge of the coffee table opposite, and at length manages to catch my eye. "Malcolm. What do you think they want us to do next?" he asks conversationally, and I answer belligerently, "I don't know." Adam counters calmly, "Well, I do. They've done this deliberately, they're expecting us to go looking for revenge and take our eye off the ball, but we're not going to play by the rules that they set." I stare at him incredulously, before snarling, "It isn't a game!" I will not allow them to do this to Colin…he deserves so much better… Adam shouts back, "Yes it is, that's exactly what it is, a big elaborate game. And the question we always have to ask ourselves is, what do they want us to do? How do they want us to react?" I look at him, stunned by his vehemence. "What do we do, Malcolm?" he presses. And resignedly, my anger draining away to be replaced by the numbness of exhaustion, I reply, "The opposite."

Adam nods, "That's right. If we kill one of Collingwood's men in revenge, if we even kill Collingwood himself, then we will have achieved nothing. We have to wait, we have to wait until we're ready, and then in our time, when we decide, we'll strike and we'll finish them once and for all. But until then, we have to act normal. We have to carry on as if the hanging was a suicide, which the police report will inevitably say it was. They'll know we know, but we'll smile at them, and we'll carry on smiling at them, and if you can't deal with that then you're no good to me." I look away, unwilling to meet his eye, and he prompts me, "So smile." I feel sick at what he is asking me to do: I can't. I won't. Even Ruth protests softly, "Adam," as I tell him, "I can't." He doesn't drop his gaze; instead he focuses even more attention on me, his eyes burning into mine like hot blue lights. Ruth tries again, "Adam!" and I finally find my voice, roaring "I CAN'T!" and getting up to flee, or fight; I don't know which, until Adam catches hold of me by both shoulders.

Zaf, ever Adam's faithful lieutenant, is on his feet too; tension crackles through the air like static electricity before a storm. Adam says it again, holding me firmly between his hands. "Smile." We stand there, sizing each other up like boxers; finally, I look straight at him through the tears that are threatening to overflow at any moment, and ask, "Would you have smiled at your wife's killers?" Immediately, I know I have landed a body blow; his eyes change, becoming moist, but no less fierce as he silently scrutinises me for the longest time. Eventually he says hoarsely, "Yes. I'd have smiled at Fiona's killers if it had been necessary." It is my turn to scrutinise him, now, but I already know he is telling the truth. There is nothing, nothing that he would not have done to exact his revenge on those who stole his wife, and the mother of his child, from him. "Yes, I believe you would," I concede wearily, giving a ghastly and thoroughly unconvincing twitch of my right cheek, as if suddenly afflicted with St Vitus' dance.

Adam says in response to this pathetic attempt, "That's good. Work on it," before releasing me, and turning to the others. "Right, Colin found something out in his van, we need to know what it was." I think of the raw data feeds transmitted just before he went off the air, and know my work is cut out for me. Before any more can be said, though, there is a soft, but persistent, knock on the door, and Adam growls, "If this is one of those charity people…" as he opens it to find an attractive young woman announcing, "I'm Jenny, the new nanny for Wes, I was told to come at seven for a chat." Adam says nothing at first, and rather less confidently, she asks, "Have I come at a bad time?" Adam replies smoothly then, "Not at all," as he stands back to let her in; Ruth jumps up to explain, Harry and Zaf instinctively withdraw to a dark corner of the room, and I slip out onto the terrace while no-one is looking, desperate for a chance to compose myself.

Outside, it's a lovely, though cool, summer evening, and I take in great lungfuls of air as I knuckle the treacherous tears from my eyes, before looking out over the river towards the endless London skyline, which Colin will never see again. It's very strange, to think that someone can be so intrinsically part of one's life, living under the same sun, working side by side for the best part of a decade, and then one day, be gone forever, just like that. I feel completely exhausted after my encounter with Adam, even though I know he's right, but I don't regret shouting at Harry. He had it coming, I tell myself, and keep telling myself that even as I hear the door behind me slide open and light, though tentative footsteps, coming towards me, and the fragrance of a garden after rain wafts in my direction. My hands grip the railing, but I don't turn round as I tell her in a dull voice, "Just leave me alone, Ruth." The footsteps stop, and after a moment she says, "I only came to see if you were all right." This strikes me as such an incongruity that I laugh, a harsh sound, and reply angrily, "Oh, yes, I'm fine. Never been better, in fact. My best friend's been murdered, I'm to smile at his killers, and just to round things out nicely I got to watch the woman I loved more than life itself, making overtures to our boss. Spirits always did put you in the mood… frankly, I'm surprised you showed any restraint at all, the way you've been behaving lately." That's it, Wynn-Jones, tell her what you really think…

There is a charged silence, before she says calmly, "You ended it, remember? So what I do, or whom I do it with, is no business of yours." I know she's right, but I hadn't counted on her moving on to Harry so fast, or so blatantly. Even Zaf had been uncomfortable, sitting there beside them. "Go away," I tell her, refusing even to look in her direction, "Please, Ruth." For a moment I think her footsteps are receding; then I know that she is coming towards me, and the tension in my neck and shoulders invades the rest of my back as I feel her touch me. Once, I would have rejoiced at the slightest hint of contact. Now, I flinch away from her hand on my elbow as she tries to turn me towards her, and after a moment she switches tactics, swiftly ducking beneath my rigid arm to stand between me and the railing, her body almost, but not quite, touching mine. I look down in surprise at the unexpected movement, and our eyes meet properly for the first time since hearing of Colin's death. Hers are large and luminous in the golden light of dusk, and once more I find myself, against my will, drawn into those extraordinary blue-green depths. "I know you don't want to speak to me, but I am truly sorry about Colin. I really am," she says softly, and then she is gone, slipping away like the chimera I sometimes think she must be, leaving me shaking with so many feelings that I can't differentiate grief from desire, or love from hate.

A few minutes later, Adam walks onto the terrace. "I saw you slip out here, earlier, but I've been so caught up sorting things out with Jenny… I'm sorry if I came over too strong, but I need you, Malcolm. I know it's easy to lose sight of the bigger picture when Colin's been murdered, but the country's in graver danger than we know. I need you, and all of us, to be on our best form, because I think there's a lot more to deal with before we fight our way clear. The stakes this time are incredibly high." I stare out over the Thames, slowly flowing on its way as it has done for eons, and point to the few faint pinpricks of starlight that are visible through the light pollution of one of the world's greatest cities. "There's Castor, and that reddish one is Pollux…the Twins. I always wondered what it would be like to have a brother, you know. And then, I met Colin…" My voice catches, and I fall silent, struggling with my upwelling emotions.

Beside me, Adam nods, and waits until I have regained some semblance of control again. "I…I haven't forgotten that we're in the middle of a national crisis, and I won't, just as long as Colin isn't forgotten either. His death…it's so senseless, so arbitrary, so brutal…and it will be so very hard on his family, first to be told he committed suicide, and then to learn the truth. I won't let it be for nothing." Adam looks at me directly, the blue intensity of his gaze like a gas flame, and says quietly, "And neither will I, Malcolm. I promise. Now, I hate to do this to you, but we need to go back to work: Jo's still in the field, for one thing, and she needs us. Are you OK to drive in, or shall I call a cab for us both?" I thank him for his kind offer but assure him that I will manage in the Rover, seeing as I haven't drunk a thing all evening, to which he rejoins as we leave his flat, "Perhaps you should, once you're home. It'll help you sleep."

The night shift on the Grid is a busy one: a couple of hours after we return, Jo rescues Rowan from an abduction attempt, or so her carefully coded text message informs us, and she has gone on the run. As for Adam, esteemed team leader and recent widower, father of one small boy and Jenny-the-nanny's new employer, he is busily pursuing his own pleasures with that cold-looking woman from Six, if I'm not much mistaken. He has evidently forgotten all about his speech exhorting me to smile even if it was killing me, and turned his attention to other, more interesting matters. He doesn't even see the gapingly empty desk next to mine as he walks past, asking Zaf for an update on Jo. Just as Zaf replies, "She's found a bolt-hole, that's all we know," Adam's private mobile phone trills, and he answers with a smile on his face and an even bigger smile in his voice, "Ros? Dinner? I tell you what, I've got a better idea. Why don't you come over to mine?" She must ask something about Wes in reply, for he chuckles, "No, I'll make sure he's asleep…OK, great, I'll see you then. Bye." I wrinkle my nose in disgust; this is a very late dinner, indeed. As he turns to leave, Adam pauses at my desk just long enough to say, "Malcolm, email me Jo's location details, would you?" and then he is gone off to do who knows what with that unpleasant woman. Any respect he might have won from me earlier in the night dissipates in his wake: why, he's no better than Harry, always planning his next conquest. Why hadn't I seen it before? With biting sarcasm, I say, "Right," to his retreating back; I can't be sure if he heard me or not, and quite frankly I don't care.

The rest of the night passes in a blur, as if the world is not quite in focus. I go to briefings, but I don't remember what was said, or by whom; I log hours of surveillance footage, but have no real idea what I'm looking at. The only thing keeping me here at all is the fact that Jo is out there somewhere, scared, alone, and in very real danger: and Colin had loved Jo, worried about her, and spent much of his spare time recently in coming up with ways to protect her. Tonight, I am watching over her as much for him as for myself, and when she finally messages her location I am relieved to hear from her. I email Adam the details and hope he isn't so far gone with the Meyers woman as not to be able to get to his laptop and pick up the message, and then I turn in my seat to tell Colin she's alright, before it hits me again: Colin's not here. I must make some sort of sound, for Zaf turns towards me. "Malcolm, go home. The night desk officers can take over now, and you look done in." I glance at my watch and see that it's close to midnight. Without a word, I shut down my array and leave; Jo is safe enough for now, Zaf has already gone back to his screens, and I haven't seen Ruth, or Harry, for hours. I am so tired that I have to concentrate fiercely as I pilot the Rover towards Hampstead.

Once I'm home, though, the last thing I want to do is sleep. I am quite alone, for Mother, with tedious predictability, has so far resisted all Aunt Emily's efforts to send her back to London, and with the latest health-scare campaign in the tabloids, she has absolutely refused. Now, though, I would welcome her company…anything would be better than the feeling of isolation that has been threatening to overwhelm me all day. I wander aimlessly about the house for a bit, looking for a distraction; I can't bring myself to go into what was once my favourite room, with its fine fireplace and Adam ceiling, for it holds too many memories. Colin, sprawled on the ox-blood leather Chesterfield opposite, his garishly odd-socked feet stretched towards a cheery blaze, toes wiggling with enthusiasm as he describes his latest invention, his eyes alight with excitement; or asleep, his spectacles perched on his head, a row of empty beer bottles lined up neatly on the low table between us, worn out after the conclusion of an operation. And then, there's Ruth…Ruth, wrapped in my old dressing gown, fresh from her bath, creamy skin catching the firelight as she lays out a carpet picnic of jacket potatoes and cold cuts from Fortnum's, while I open a bottle of Bordeaux, and we eat and laugh and touch until a flame of a different sort springs up between us, and too hungry to move to the bedroom, we take each other, right there… I must find something else to focus on, or I will go stark, staring mad.

The longcase clock in the hall strikes one, and I know that I will not sleep tonight. I haven't eaten either; I haven't eaten all day, in fact, and my stomach is protesting fiercely. Unwillingly, I trail into the kitchen and open the refrigerator, surveying its starkly empty white interior. Since Ruth and I went our separate ways, I haven't felt much like eating and without Mother to do the odd spot of cooking or shopping, I have been subsisting on a meagre diet of Bath Olivers, apples and cheese; now I'm down to the last of the large, bland crackers. I scrape a layer of butter over three of them and dig out a bottle of Chateau Lafite: only the best will do, tonight. I cast about for something to occupy my mind, and remember that I still have Colin's MP3 player in my jacket pocket, discarded carelessly over the banister. Collecting a wine glass on the way, I carry it all upstairs, locking myself into my wing of the house, and then into the most private sanctuary of all: my music room.

It doesn't take me long to hack the MP3 player, now that I know what I'm looking for. I quickly bypass the fingerprint sensor, hack the lockscreen with a few strings of code, and I'm in. And glory be, there they are, by far the biggest files saved on the device: the final four episodes of Doctor Who, as yet unaired in this, or any other country. Picking up a sleek remote, I push a button and the panelling at the other end of the room rolls back silently to reveal a large LED screen. Next, I hunt through a small box of connectors and USB adapters until I find the right one for the MP3 player, and hook it up to the television. I drop into my chair, pour myself a very large glass of wine, and press Play, closing my eyes as the familiar opening theme thunders from the speakers. Oh, Colin, you should be here too...

I watch the second part of the impossible planet episode: I'm fine. I watch the next episode: I'm fine. I skip the following episode, something about the London Olympics and disappearing children, once I realise that the Doctor is going to be absent for most of it, for I need my Doctor tonight. The penultimate episode really gets my attention, even if I have finished most of the wine; Daleks and Cybermen on Earth, a secret government organisation in Canary Wharf, and the Doctor on top form. And then I watch the season finale, and I am in no way fine, for the Doctor loses Rose, unexpectedly, in the midst of saving the world; and for the first time since learning of Colin's death, I have a metaphor for how I am feeling. Like the Doctor's anguished scream as Rose hurtles towards the Void; like the desolation and disbelief on his face as he surveys the wall that represents separation from her forever; like the shocked blankness of his expression as he finally walks away, shoulders hunched in defeat. I can't watch any more, for my eyes are blurring with tears and I can't get my breath and it feels as if a tonne of weight is crushing my chest as with an unearthly howl of my own, I give in to my grief with great, gasping, shuddering sobs that rip my throat raw. I don't know how long it lasts, nor for how long I sit, afterwards, staring at the empty screen; I only know that I am so exhausted I can't move, and yet I feel as if I may never sleep again.

I sit there, motionless, until I can't bear it any more, and moving like a very old man, I drag myself out of my music room and shuffle unsteadily down the hall towards the bathroom. I stand under the shower for what seems like an eternity but in reality must only be fifteen or twenty minutes, before I get dressed with the mechanical precision of an automaton, find my keys, and drive towards Thames House while wishing I were a Cyberman or Dalek, devoid of emotions and wrapped in a metal skin that shuts out all sensation. Machine logic from a machine mind, that's what I need, not this constantly roiling state of unpredictability that humans call 'being alive'. As I drive, I concentrate on compartmentalising the pain of my loss, locking it away into the deepest recesses of my psyche, striving for the calm and detachment I know I am going to need today, and every day that I choose to keep walking back onto the Grid. By the time I reach the pods, a little after six a.m., I have mustered enough self-possession to nod at my co-workers while studiously avoiding their sympathetic looks. I don't want their sympathy; I want them to say that everything we do on this op, we do in Colin's name. Above all, I want them to remember him. Already, I miss him so much it's shocking: Colin, my almost-brother, closest confidante, brilliant colleague, and very best friend.

A/N: the opening snippet of Latin translates as 'He went away without saying goodbye.' The Doctor Who episodes referenced are the last four of Season 2, which culminated in Doomsday. Whovians know I need say no more. Colin is quoting Marvin, the Paranoid Android, from The Hitchhiker's Guide to the Galaxy by Douglas Adams.