Hopelessly dysfunctional sibling relationships seem to be a nigh-constant theme, with me. Apologies to my actual sister.

The first time Gabriel ran away from home, he was less than a billion years old, and he left a note saying "So long, suckers! (Tell Mike that I still owe him for the sword)."

Michael was rather displeased by all this, though their Father responded with the sort of calm indulgence that belies a raging headache and the need for reassurance of the validity of one's parenting skills. Aspirin had not yet been invented, and blatantly obvious white lies were equally unforthcoming, so in the end Dad went off to have a minor personal crisis and Gabriel was left to his own devices. He proceeded to fly loops around a couple of pulsars before counting how long he could stick his wings into a dwarf star without burning himself to cinders. Presently, he tired himself out, returning to what would eventually become the Garden with his tail – metaphorical and otherwise – between his legs.

The sword in question was of the flaming variety, doused during an exceptionally brutal prank war between all four archangels – one of a series that had been escalating since the universe's creation, in fact. The battle culminating in the breaking of the sword had begun when Lucifer had been told that he was not allowed to pull Raphael's hair. He had thrown a particularly spectacular tantrum, concluding in a swift punch to one of Gabriel's faces. Gabriel, ever the more rational and level-headed of his siblings, had retaliated by planning carefully ahead, taking it upon himself to study all available resources before unleashing his offensive. This led to his discovery of the joys of bonding hydrogen and oxygen – and to the corresponding discovery of what happened when his newfound toy hit Lucifer squarely in the westernmost eyeball.

A thoroughly indignant Morning Star happened. Also, one of the first known examples of collateral damage in the history of anything. Collateral damage took the form of Michael's favourite weapon sputtering its way into a somewhat anticlimactic new existence as an unhappy lump of charcoal.

Predictably, Michael was consumed by incandescent fury. On these occasions, numerous as they proved themselves to be, Gabriel always found it far less hassle to slip away unnoticed than to confront anyone, a trait that was probably – or so he would tell himself repeatedly in the ensuing millennia – hereditary. Considering the entire family's propensity towards acts of mindless violence, the logical conclusion to which he took this was that getting the Hell out of Heaven, somewhat more permanently than usual, was a pretty flawless plan. After all, sometimes a little peace and quiet was a good thing. And Michael really had loved that sword. And Dad never did let him play near dwarf stars.

Since then, Gabriel has gotten into something of a habit. A rut, certain people might say, were they feeling distinctly uncharitable. Gabriel himself is not uncharitable, but he does appreciate the finer things in life, and sometimes the finer things do not include a million curious cherubim rooting through the contents of his metaphysical bedroom. Still, it's a couple billion years later, the next time he makes another, equally short-lived break for it, and then there's a good steady period of domestic bliss until the earth is formed, at which point the very thought of the commitment that might entail has him throwing up a little in the back of his mouth and bolting for the stars all over again.

Raphael entices him back that third time with promises of lightening and magma and maybe even eventual sentient siblings, so Gabriel grudgingly goes with. But, by the time the iron and sulphur are doing their thing in the cores of a good few alkaline vents, he's already beginning to see the downside to having a sudden influx ofbaby brothers and sisters. Especially those of the dauntingly corporeal variety.

He takes off, and only comes back during the Precambrian. They tell him that he's missed far too much, and throw the divine equivalent of an awkward family dinner party to welcome him back, but nothing really helps. Even the youngest angels have grown up in Gabriel's absence; he barely knows their faces, not the way he did once, when every detail was written on the heart. He fumbles for their names, and when he can see them becoming embarrassed for his sake, he snaps – which is mildly cathartic, if nothing else.

Time stretches out like this for a while, largely meaningless. One morning Gabriel finds himself forlornly dangling his toes in the seas of Second Heaven, unable to work out quite why he's drowning in melancholy, but depressingly certain that the only hope he has of shifting it is to put a good few light years between himself and the newly developing terra firma.

"Little brother," says Lucifer, "you have issues."

He agrees wholeheartedly, though privately he thinks that the sentiment might be mildly hypocritical. Lucifer spends half his time arguing with Michael, and the other half begging for his attention – largely because Michael is the only person in Heaven who doesn't devote it to Lucifer in excess. That aside, leaning on his brother's shoulder feels like exactly the course of action that should help, the kind that will be promoted by self-improvement books billions of years into the future, when everyone will be emotionally competent, probably. Thus, Gabriel feigns indifference – which is the best possible way to capture Lucifer's attention. He shrugs, focusing on dashing the water with his heels and making neat concentric ripples on its surface so as to give himself an excuse not to look up.

Lucifer takes a flat stone and skims it across Second Heaven's waters. It splits into two equal pieces which skate around each other in increasingly intricate patterns composed entirely of figures of eight. A flower blossoms out of the ocean, petals daintily rimmed with sea foam, and freezes into cold, crystalline feathers of ice. Then the whole thing explodes in a shower of magnesium sparks.

"Show-off," says Gabriel.

"Just trying to distract you," says Lucifer.

"Teach me," Gabriel replies.

He disappears off a few times after that, but only in a half-hearted kind of way. He tells himself that it's to see if it will make him feel any better about anything, but there isn't much of anything to feel better about, other than a creeping sense of purposelessness and an inability to communicate with his Father. Michael assures him that both are normal, at his age, so Gabriel is forced to admit that all he's really doing is maintaining his reputation amongst the lowest choirs, who are perpetually in awe of the moodiest, most aloof of their commanding archangels. Although, even that's fading, because Lucifer is giving Gabriel some stiff competition with all his droll asides and his weird, distinctly enigmatic type of nonchalance.

It's K-T that's the real turning point, when the rules begin to change and the game gets deadly. Mass extinctions are fun for the entire family, inciting crazy corkscrew joyrides through the plumes of ash clogging the atmosphere, and furtive discussions about which species to bid on in the illicit Heavenly sweepstakes (Gabriel is always amazed that no one realises that Dad is well aware of both these activities, and doesn't care about either). The festivities are only heightened by the knowledge that this is the dawn of an epoch of mammalian dominance, and everyone's always so excitable when it comes to mammals. The cupids think they're cute; the seraphim revere them for the prophesied achievements of their eventual descendants. Gabriel finds it difficult to rejoice over a family of overgrown rodents. He loses a little faith over it, because if there was anything that the entire celestial household, Gabriel included, was all geared up to love, it was mammals.

He ends up sat on the sidelines with Lucifer, sparring and learning how to divert the course of a tsunami wave on a wingtip. The Tertiary period is fleeting, comparatively, but it gives them ample time to sit around and indulge in intelligent conversation. Which is, Lucifer opines, sadly lacking on Earth. Dad's far too busy with work to waste time talking (though Gabriel has a sneaking suspicion that He might, if Lucifer asked when Gabriel wasn't around), and though Michael is clearly capable of it, he turns up his nose at anything resembling an engaging discussion. Besides, Lucifer's taken to ignoring Michael, in some bizarre and misguided attempt at reverse psychology. Raphael, of course, would rather swamp a continent than debate theology.

The real kicker being that not a single one of them understands why a pair of angels would want to talk theology in the first place.

Theology gradually devolves into whining. Gabriel can't stand his family; Lucifer can't get anyone not to stand him. Other than Michael, that is, and Gabriel is entirely sick of hearing about Michael, even if it's better than hearing about mammals. The Neogene begins, and they pledge never to hold back on insulting each other, at least. Although Gabriel knows with utter certainty that Lucifer has never – not once over the course of his entire existence – held back on insulting Michael, he's perfectly happy to pretend not to notice, because being Lucifer's second favourite brother is infinitely better than being nobody, and – on contemplation – infinitely less dangerous than being first.

Gabriel, Lucifer says, is a melodramatic, overgrown toddler who can't think of a better solution to his problems than to leg it to the dull end of nowhere, seven galaxies away, bare minimum. Also, his sense of humour is terrible.

Lucifer, Gabriel snaps right back, craves the attention that he professes to despise, and wouldn't recognise a pun if it stood on his pinions and offered him an advanced class in Viennese waltz. Also, the rare moments that Dad spends in his older children's vicinity are inevitably spent with him.

"Does that bother you?" Lucifer asks him, with a smirk like a slash carved all the way across his smug face.

"No," Gabriel says quickly, and goes back to dropping oversized hailstones on the heads of various Neanderthals rather than having to properly reply. "Screw you," he adds for good measure, and Lucifer's laughter makes the Neanderthals look about in terror as the ground rumbles beneath their feet.

The first time anyone thinks to invite Gabriel to run away from home with them, he and Lucifer are stood on a tall plateau overlooking the arid plains of proto-Africa, and a pair of idiot homo sapiens just went and decided to get their entire species chucked out of the Garden. Funny thing to exult in, Gabriel thinks, but Dad has a perverse sense of humour, and by now Gabriel's sort of fond of those overgrown rodents, and it's not like he hasn't always been fond of Dad. So, when the time came, he bowed along with the others. If only in anticipation of what the world might become in the next couple million years.

"Come with me, brother," Lucifer pleads, hands two little dead weights on Gabriel's shoulders. "Our Father is sorely mistaken, and I'd take far greater pleasure in showing him that together than apart."

Gabriel ignores this bout of blasphemy, because he's never really cared for the whole sanctimonious archangel deal, not like Michael does. "You just don't know when to quit," he says, rocking the marginally disgruntled yet totally apathetic look instead. But he sighs, like trying to scrape the air out of his vessel's lungs before it stagnates, and that pretty much ruins any pretence that he was cultivating.

"I'll never quit," Lucifer says evenly, calm and reasonable and mildly sardonic as ever. "What I'm doing is for all of us."

"Bullcrap," Gabriel retorts, and shrugs the damned hands away. "If you cared about any of us, you wouldn't have declared war on your own Dad."

He had meant to say 'on your own brothers', but knows that that line of argument would be doomed from the start. Lucifer hasn't declared anything on anyone yet, save God. That will come later, once he's scraped together all the gullible schmucks he can in one big Heaven-wide recruiting drive.

"Dad never cared about you, Gabriel," Lucifer is saying, eyes wide and earnest. He's being a poisonous little brat about this whole thing, and there's no denying it. "Don't you want a chance to show him that he should?"

"Not especially," says Gabriel, and is on the edge of the plateau and kicking his heels out at the empty air before Lucifer can see his expression.

If there's one thing that Lucifer possesses in abundance, though, it's dogged perseverance, so they end up seated together, staring out at the seemingly endless brown wasteland like it contains all the secrets in the universe, even the ones that they don't know already.

"You know," Gabriel begins, "you probably deserve credit for fighting, at least." He makes a lazy, half-hearted gesture at the world in general, before letting his hand fall back down at his side. "I mean, not everyone could call Adam a list of names that inventive, then up and disobey a direct order from Dad. Round about the third day of sulphur, and whatnot, all raining from the sky, I'd've probably just cut my losses and apologised. Maybe started small, with a fruit basket and a note, y'know?" He trails off, because Lucifer isn't responding. After a moment of awkward silence passes, an exceptionally ineffective litmus test for gauging the current state of his brother's attention span, he persists. "Mind you, I'd go there in person eventually. I mean, it's hardly a valid request for forgiveness if you don't even submit it face to throne, right?"

Lucifer remains silent, expression obnoxiously vacant. Gabriel waves an experimental hand in front of his face, and receives an eye roll for his efforts.

"I'm tired of being taken for granted, brother."

…Which is so unexpected that Gabriel nearly falls off the edge of the plateau. "Come again?" he splutters, incredulous.

Lucifer's features contort into an ugly mess, and overhead, the clear sky creaks and rattles like it's trying not to fall to pieces.

"You wouldn't know, Gabriel," he mutters, but he schools his face, returning once more to eerie composure. For someone who places so much value in honesty, Lucifer sure does love his inscrutable expressions. "No one ever wanted anything of you. What are you? A messenger. It may have slipped your notice, but there's no one yet to messenge. You haven't disappointed any of us." He sniffs, pointedly. "You haven't had the chance."

"And you've been expected to do what, exactly-?"

"I lead the powers!" Lucifer throws himself to his feet. The melodrama would be sickening, but Gabriel felt pretty sick to begin with. "The ophanim sing their praises in time to the beat of my wings; I am the Morning Star that lights the Heavens. All bow before me; all must avert their eyes from my glory."

A herd of something mammalian is meandering its ponderous way across the plains, just visible in the middle distance. Gabriel inhales deeply, and it smells like potential rain. The humans will be happy. The whole business with the humbleness and the clothing will run an awful lot smoother if they invent a means of doing the laundry.

And Lucifer, probably having rehearsed this whole spiel, is making out that he has it rough.

"I'm pretty sure that there's a word for that," Gabriel informs him, still sat, still steadfastly refusing to look behind him. "Begins in 'huh' and rhymes with 'gnubris'."

"I've sinned worse," Lucifer says, silky and treacherous, just a breath away from Gabriel's left ear.

"There's a difference between teenage rebellion and full-on rebelling," Gabriel tries, because maybe he can be a substitute Michael, if he's forced. Martyrdom has no limits.

"I get that," says Lucifer.

Having reached something of an impasse, they fall silent once more. The herd wanders out of view. Maybe the whiff of moisture he'd detected was a fluke, because Gabriel tastes the air again, and it's desiccated.

Lucifer is still ominously close when he murmurs, "I don't want to have to kill you, Gabriel."

Gabriel actually laughs at that, because it's the epitome of the kind of thing you don't spring on a guy when he's well within stabbing distance, and it's never been more blatantly obvious that Lucifer has no social skills to speak of. Forever the reject angel; once upon a time that would even have been funny. "You're not so bad yourself, featherbrain," Gabriel says out loud, grinning as wide as he knows how. It diffuses what little tension a bad joke is capable of diffusing. After that, they sit together for a couple more minutes without really saying much, but with a vague sense that this kind of wordlessness is more comfortable than the alternative.

Finally, Lucifer ruffles Gabriel's hair, and disappears. He doesn't say good bye, or even apologise.

Gabriel never really gets over how patronising that is.

The ensuing war is harrowing, to say the least. It's Heaven's first bona fide civil conflict. Lucifer rallies approximately two hundred angels, but it may as well be half the Host, given their uncanny prowess at skewering the loyalists. Even cut off from Heaven, these soldiers are high enough up on the food chain to be absurdly capable. Predictably, the death toll is only exacerbated by the laws against fighting sans hosts; that just results in the majority of the early humans dying alongside their celestial brethren. By the time Lucifer gets shoved in his custom-made jail cell, it's getting a whole lot easier for Gabriel to remember his siblings' names.

Not that he has any reason to, once Heaven reaches some approximation of ceasefire (inasmuch as having utterly annihilated the opposition can be referred to as such). Home feels downright claustrophobic without Lucifer's presence, and the cloying sense of being trapped in his own skin grows in searing intensity every time Gabriel is forced to look at the blackened imprint of a dead angel's wings. Michael shrugs off every attempt to talk about it, claiming that he has very important business to attend to. Gabriel is fairly sure that 'very important business' refers to long periods of intense brooding overlooking remote glacial lakes, but the one time he presses, he ends up with charred wingtips and an abysmal headache for the next seventy two hours.

Raphael tells him to get a hold of himself.

In the end, he never bothers going to talk to his Father about it. Instead, Gabriel falls back on his infallible coping mechanism, and runs. It's only a week after armistice day – practically a record, even for him, in terms of sheer effrontery, especially given what everyone's just been through. Not that any of them seem too broken up about their losses, save the nuclear family, and even that's just an attempt at playing the pity card, and a fairly laughable one, at that.

He leaves a note saying "Smell ya later! Should he ask (and believe you me, kids, he will – probably before concern for his favourite little brother ever worms its way through that thick skull of his) tell Mikey to forget about the Goddamned sword."

He's kind of worried that he still capitalises the 'G', but then, old habits die hard. Deserting for good will require small steps, and all that. Small steps, as it turns out, consist of moping at the edges of civilisation for a good million years, indulging in every sin that he'd never thought to try, losing the divine temper in favour of suave unflappability, moonlighting as a pagan god (mentally, he settles for a small 'g') and – ultimately – getting immensely, pleasurably, unrepentantly drunk the night before what was meant to have been Annunciation.

Mary never works out why her personal archangel is a renegade with a bad hangover and an attitude problem, and whichever poor schmuck attempts to inform her of her pregnancy three quarters of an hour after Gabriel has already done so probably had it coming. Accept no substitutes.

In terms of people Gabriel still has the capacity to care about, Dad's been focused on a very small portion of humanity to the exclusion of all else, for a very long time. Gabriel had sort of hoped that He'd be outraged at His ex-postmaster intervening in that, but all he gets is radio silence over every angelic station he tunes in on. Apparently, the Lord of Lords is getting apathetic in his old age.

Which, if unexpected, is at least patently in character. So Gabriel counters apathy with apathy and spends the next two millennia as monster – literally. It's the angelic equivalent of asking your inheritance early and getting a job as a swine herder. Besides, those pagans know how to party. There's a transition period at first, of course, for a couple centuries at least, during which he keeps it all low-key: no blabbing about how he used to be powerful and important, no matter how much alcohol he consumes; any attempts to win his true name are met with a longwinded and increasingly convoluted anecdote about why exactly his parents settled on 'Steve'. After that, as Dad's influence wanes further and Gabriel finds himself increasingly desperate – or at least, increasingly miffed – all reservations crumble. He starts doling out the flashier karmic judgements, resolving never to perpetrate a crime that doesn't make somebody laugh, even if it's only himself. If he's going to have a purpose in life, it may as well be ridding the world of arrogant pricks, and the legendary sweet tooth is definitely a perk to that particular career path. Suddenly, sinners find themselves dispatched of with flashing lights and a kickass metaphorical soundtrack, and the road to Hell is paved with asshattery and sugar crystals.

Either every choir in the firmament's in drastic need of an eye test, or priorities up top have undergone some major revisions, because nobody takes the hint. Gabriel doesn't even receive a sternly worded note; either no one's managed to identify him, or no one cares. Round about the Dark Ages, he gives up entirely. Time to accept the truth: he's been disowned. Officially. Exactly like Lucifer, sans the bloody and interminable conflict. It's probably becoming a family tradition – one brother per era, sent careening to their doom on a one-way trip down the axis mundi.

Just for the hell of it – always for the hell of it, and rarely with a capital 'h' – Gabriel locates the vessels a few years after the turn of the millennium. Technically, he's always known that they're integral to the apocalypse, and that their blood line's pretty much the cream of the genetic crop – these boys are pedigree. It still took everyone a while to work out their true purposes, though it became abundantly obvious the moment the lock clicked shut on Lucifer's cage. Which led to an odd little twist of logic wherein Gabriel was forced to wonder whether attempted fratricide was all part of the ineffable plan. He quickly curtailed that line of thought, though, because Dad loved Lucifer, if no one else, and no one's ways are so deeply mysterious as to override the age old force of parental favouritism.

At any rate, the ultimate meat suits of ultimate destiny turn out to be dicks. Which, given what they're based off of, is not exactly the plot twist of the century. That doesn't make it rankle any less when they turn out to be hopelessly co-dependent (it was never that kind of relationship), burdened by groundless martyr complexes (which, Gabriel supposes, sort of fits if you squint) and impossibly sanctimonious. In terms of pastiches of heavenly politics, it's rather clever. But, accurate? Not so much.

For one thing, Sam Winchester is a poor replacement for Lucifer. The kid is humourless, tedious and slow, and Gabriel takes sadistic delight – even more so than usual – in spending a few months putting him through hell. Or, a highly effective mock-up of hell, and maybe he really does take after his older brother, just for being able to dream these things up. It doesn't work, at any rate. Sam remains oblivious, Gabriel continues to loathe him with every fibre of his being, rationality be damned, and the apocalypse continues to approach, not with a whimper, not with a bang, but with the sort of cheerful inexorability of nature's most leisurely of snails confronted by the mouldering lettuce leaf of Paradise on Earth.

Paradise on Earth, on reflection, is not a terribly bad idea, so long as the rest of the universe is left untouched. Gabriel is loathe to consider the possibility that he may have grown out of playing chicken with dwarf stars.

It's Dean Winchester, in the end. Dean and Kali and Lucifer and the pigheaded idiots who might, in another life, have made a damned good family. All of it is so pathetically, laughably predictable that it puts the Buffy season five finale to shame, which is certainly an achievement.

Standing up to Lucifer, as it turns out, is not the emotional rollercoaster of unspoken hopes, last minute regrets and unwelcome hindsight that Gabriel has always assumed that it would be. Maybe it'll be worse for Michael – if it ever comes to that, and for once, Gabriel sincerely believes that it won't, if only because the law of averages has to come into play eventually in terms of victories for the good guys. In retrospect, downing the Free Will kool-aid is probably a major boost to the misguided optimism.

All that aside, fighting Lucifer turns out to be more akin to terrifying terror with a double shot of horrifying than the family reunion he had expected. Still breaks his heart when he has to look his brother in the eye and tell him that their Father was right, though. In a way, that's almost worse than the excruciating death that one of them will inevitably suffer in the next five minutes: Gabriel picking their Dad over his own brother. (His vessel's tailor-made, human-free in order to maintain the one hundred percent natural look. Gabriel has no unwitting co-pilot. So, there's no real excuse for the bile in his throat.)

It's as he monologues just enough to hold Lucifer's attention, a talent that he really wishes he'd possessed in the first few billion years of their existence, that he realises. He's on the right side, for once, and willing to die for the cause. If ever there was an objective moral high ground, Gabriel's got dibs on a penthouse apartment, one badass roof garden and a neighbouring Biggerson's pie bar up there.

He supposes that there's a first time for everyth