Arthur sets up the base the day they find out Morgana's a carrier.
They're having dinner, Uther, Arthur and Morgana, and they could almost pass for a happy family, almost, except for the way the way they're talking, carefully calm and polite, swapping small talk and the usual pleasantries but never actually saying anything, never even looking at each other.
(Gwen isn't there, of course, but she's been to the Pendragons' before, can fill in the gaps in Arthur's story with little effort.)
There's no warning, before it happens, no indication that this dinner is going to be any more than the painfully awkward affair it usually is, Uther cheerfully oblivious to his daughter's quietly steaming resentment.
There's no warning; Uther's just nodding with polite disinterest at Arthur's recounting of the latest development of the disease when Morgana gets abruptly to her feet.
Arthur trails off. Uther stares at her, bemused.
"Are you all right, Morgana?" he asks. "Do you have something to add to the conversation?"
Morgana just smiles sweetly, dangerously, says, "This," and leans across the table to spit in his face.
For a moment there is nothing but Uther's spluttering outrage, Arthur's shock that Morgana's finally, finally snapped, and then.
(Arthur won't be able to describe what happens next, will break off and cough gruffly and say, "Well," and, "You know," with only the faintest crack in his armour, and the most horrible part is that Gwen does know. Her father was among the first, and every day since Elyan left she has dreamt of him meeting the same fate.
The not knowing is the worst part, she thinks.)
Morgana twists around as Uther writhes and moans, curled up helplessly on the ground, but even through his horror Arthur is quicker. He's been trained for this, after all. His finger's on the trigger of his taser before Morgana can get close, and she drops soundlessly to the ground. He's careful not to touch her bare skin as he lifts her into his arms, carries her out of the house.
"And here we are," Arthur finishes, dragging his gaze up from Morgana's still unconscious body, laid out on Gwen's kitchen table.
Gwen tries to touch him, then, tries to offer some semblance of comfort, but Arthur- he doesn't flinch, exactly, but he turns away very deliberately, and Gwen understands, withdraws her hand.
"I'm taking over the old military compound on the edge of the city," Arthur announces, but Gwen doesn't comment on the abrupt change of subject, allows him to cling to the remainder of his dignity. Because after all, what else do any of them have here, at the end of the world?
He asks her to be his chief of science, says, "We need you, Gwen, we can't do this without you," and Gwen doesn't even hesitate before saying yes.
"Merlin's insisted on joining you, of course," Arthur informs her, with the kind of exasperated fondness he'd never, ever admit to. But that's another thing Gwen's letting him get away with, another secret she's letting him keep. "Do us a favour and don't let him near any of the important stuff, yeah?"
Gwen smiles, something she thought she'd never be able to do again, once, and says, "Of course, Arthur. I wouldn't dream of it."
They've pulled someone in, a ragged looking man with a too cheerful smile for the end of the world. Gwen knows, as she draws blood from his unconscious body, that he's different, that he's not like the countless others who've stumbled onto Arthur's compound.
"How did you do it?" Gwen murmurs, staring mesmerised at the man's blood under the microscope.
"He's clean?" comes Merlin's voice from somewhere behind her, sounding as shocked as she feels.
Gwen gestures at the microscope, bites her lip in thought while Merlin takes a look for himself.
"He isn't a carrier," Gwen says, and Merlin makes a noise a somewhere between agreement and wonder, "but there's something..." Gwen breaks off, sighing. "I don't know. And that's the problem, isn't it? We don't know anything about this disease, not really."
Merlin reaches an arm around her, pulls her in close to his side. "We will," he says, and Gwen smiles weakly, wishing she could share his confidence, his hope. Hers started to run dry a long time ago.
She takes the man – no, Gwaine, his name is Gwaine; epithets aren't for the living – out to see the quarantine camp, because he asks about them sort of sceptically and Gwen doesn't see why she shouldn't. His curiosity is kind of refreshing, honestly.
He seems mesmerised, leaning against the barrier to get a better look. He's not aroused, she doesn't think. The look in his eyes is closer to sorrow, or sympathy, perhaps, than perverted desire.
But he is fascinated, that much is clear. Gwen wonders, fleetingly, how long he was alone on the outside, what he lived through, how much of the horrors he saw, but she'll never ask.
Gwen's working on a cure. She's been working on a cure for longer than she can remember; she'd have lost track of the days entirely were it not for the logs Arthur insists they keep, successes and failures, more of the latter than any of them would like, recorded carefully for posterity, or something.
(Gwen doesn't like to think that it's pointless, that there won't be anyone left to read her words when they're done, if they're ever done, but the thought creeps in sometimes, unbidden.)
"The key to finding a cure is natural," she tells Gwaine, as she shows him round the greenhouse. He listens patiently to her explanations of everything even though she knows he doesn't really understand, which she appreciates. She sighs. "The disease is organic, not synthetic; everything we've tried just isn't working."
Gwaine puts a hand on her shoulder, squeezing. "You'll find a way," he says gently. "You will."
Gwen can't bring herself to tell him what she has suspected all along: that the cure is just too far out of their reach, that they have no hope of finding it.
"Yeah," she says, mustering a smile from... somewhere, she doesn't know. "Yeah, I hope so."
It happens on a day just like any other, of course, because that is the way of things. There's nothing significant about endings, not in real life; there are no bangs, only whimpers.
Gwen's drawing blood from Morgana, a routine procedure, and part of Gwen still burns to see her, still remembers when they were friends, remembers wanting, wanting, wanting.
"You're the only one who could do it, y'know," Morgana says, suddenly. "They'd be useless without you."
Gwen looks up, bemused. Morgana doesn't talk often; she's usually the very picture of serenity, smug smile fixed maddeningly in place.
"Do what?" Gwen asks, withdrawing the needle and straightening up.
Morgana looks up at her, her eyes darting down to Gwen's mouth, and Gwen knows what Morgana's going to do before she says, more sincere than Gwen's ever heard her, "I'm sorry."
Before Gwen can blink, Morgana's lifted Gwen's helmet and kissed her. Morgana tastes like sugar and poison and the end of all things, and Gwen imagines this is what drowning feels like, her mind wiped utterly blank, her chest aching.
Gwen moves instinctively when Morgana lets her go. She hurls herself at the door, counting on the security protocols to seal them in, to seal everyone else out.
"Why did you do that," Gwen murmurs, covering her ears to muffle the screeching of the alarms. "Why did you do that."
"Why didn't you stop me," Morgana counters, and Gwen just shakes her head, cannot answer, cannot even form words.