Work Text:
Leaning on the doorjamb, hands in his pockets, Lamb let the scene play out in front of him.
River and Shirley were bickering like two spoiled siblings, trading insults and snide remarks as if Slough House were their personal playground rather than the office where they came every day to accomplish precisely fuck all. It felt like a well-worn routine: both of them apparently irritated, insults piling up one after the other, each one dumber than the last.
"I’m just saying," Shirley said, flicking an elastic band across the desk, "if you’re going to keep coming into solid objects, you should at least warn them first. It’s etiquette."
"I didn't come into a solid object, I just... walked into it. It was… an accident," River protested.
"That’s what most men say," Shirley said, deadpan.
Neither of them had clocked him yet, good spooks they were. That meant he could stay right where he was and watch in peace, with the bored detachment of a man who’d seen this play too many times, but still found it more interesting than most things that happened in Slough House.
Cartwright didn’t stand a chance against Dander’s barbs even on a good day, though, and today didn’t look like one of those. His hair was more dishevelled than his recent usual standard, there was still a faint mark on his temple from that unfortunate encounter with the door they were talking about (one that the door had obviously won), and his wet-dog attitude looked wetter than normal.
Lamb smiled to himself.
There was a weird kind of innocence to him when he was like this, he thought, and it was irritatingly pleasant to look at. With his too-big eyes and his earnest attitude, River Cartwright looked carved out of something cleaner than the rest of them, like he’d wandered in from a different story and nobody had had the heart to send him back.
The kid was beautiful, no point pretending otherwise. It wasn’t just the face, though that certainly didn’t hurt. It was the way he stood behind his convictions, an unshakable white knight so sure they might actually save the world from the mess it was in. Moral superiority mixed with arrogance, spiced with a naivety that made both almost tolerable.
Almost.
And Christ, that stupid heart on him.
Even after everything that had happened to him - the grandfather-shaped shadow, a psychopathic father who recruited sons like soldiers and sent them to their deaths like pawns in a badly played chess match, a career flushed down the toilet - River Cartwright still tried. He still cared. He threw himself into trouble convinced that courage and justice might prevail, careless of his own safety and willing to sacrifice it if it meant one more day for someone else.
Lamb snorted silently. He honestly didn’t know where the kid got that from. It sure as hell wasn’t inherited, and it wasn’t taught. Cartwright Senior cared more about the Park and its reputation than about the people he had to crush to protect it. It had to be a hundred-percent River thing, grown in defiance of genetics and common sense.
But River was lonely, too. Terribly so, from what Lamb could see.
A flash of the boy’s apparent death after Westacres crossed his mind.
"I trust you made all the right noises to anyone expressing condolences."
"No one did."
No one did.
That no one would ever express condolences for Lamb was something he’d carefully ensured, building it brick by brick with filth, insults, and bad smells. But even to him, emptied of life and soul, it seemed impossible that a creature like River Cartwright could be so isolated from the world that no one, not even his mother, had found the time to mourn him when it mattered.
Impossible, yet also the reason Cartwright was where he was. At the Park, first, at Slough House, then. Determined to prove his worth, determined to show that he deserved that respect - that love? - that only a dead grandmother and a grandfather who barely remembered him had ever given him.
It was fucking sad, if Lamb was being honest.
It was also part of what made River so damn interesting in Lamb’s eyes. Not that he’d ever say it out loud. The kid needed to stop looking for reassurance if he wanted to survive in this environment.
River represented everything Lamb had been and no longer was. Watching him was like looking through a dirty window at a version of himself he barely remembered: idealistic, stupid, convinced the job meant something other than survival, convinced the Park would come for him if he sacrificed himself long enough for it.
To be fair, that phase had been very brief for Lamb. He’d learned quickly who to trust and who to stay away from. It had destroyed him as a human being, sure, but it had made him a better agent.
And that was where Cartwright was stuck: between the desire to become a perfect spook and the inability to understand that to do so, he’d have to leave behind everything that made River Cartwright better than all the bloody bastards who populated MI5. And even if Lamb sometimes suspected River knew this on some level, he couldn’t help but feel… admiration… for how stubbornly he insisted, every day, on making the two things coexist: being naïve, reckless, and damn near heroic, and trying to force the Park to change instead of adapting himself to it.
"Fuck you, Dander," River was saying, after Shirley had lobbed the same elastic band at him again. He failed spectacularly to catch it, and it smacked right into his already-bruised temple.
"Oh for God’s sake," Shirley said. "Do you want me to get you a helmet? Or maybe just bubble wrap the whole building so you stop injuring yourself with furniture and stationary?"
River just looked at her, irritated, almost pouting.
Attractive, Lamb admitted.
That was another thing Cartwright definitely was, in the most irritating way possible. One that made Lamb feel like a dirty old man far more effectively than poor hygiene and unrestricted flatulence ever could. But certainly not in any way he’d ever dignify with action. Christ, no.
Even if Lamb was fairly sure that with the right tone, the right attention, and the right validation, Cartwright would drop to his knees and do whatever Lamb asked - daddy issues stacked like a goddamn Jenga tower - Lamb wasn’t that kind of bastard. The kid deserved better than having someone twice his age come in his mouth.
And if the image sent a shiver through him, woke parts of him that had been asleep for what felt like millennia, age at least usually gave Lamb the ability to ignore this kind of thoughts and move on with his life without blue balls ruining his day.
Still, how could he deny the double pull there, the one he hated himself for recognising so clearly?
The urge to protect River, to keep the kid safe from the worst of it, from becoming what the Park eventually turned everyone into. And alongside it, darker and more shameful, the desire to own him, to control him, to have all of Cartwright’s unwavering dedication focused on himself, held in his hands, shaped into whatever he wanted and needed.
Lamb would never go there. He was almost sure of it.
But some nights, when the building was quiet, the bottle nearly empty, and the past refused to stay buried, he let himself imagine a different life, just for a few moments. A life where he hadn’t fucked everything up beyond repair. A life where he was the kind of man who could actually keep someone as pure as River-fucking-Cartwright in it and be happy with it.
On those nights, his mind supplied River’s image, all fire and awkwardness, stumbling through the world with that infuriating decency intact, and his hand went to his own cock, guilt and desire tangled inside him, leaving behind a bitter aftertaste and the ache of wanting something better, something cleaner.
Sometimes, you just grasp any spark of perfection. Lamb remembered. And Lamb was fucking lost. He could try to deny it, try to ignore it, but he was too good at his job to fool himself.
Shirley laughed at something River snapped back, and that was when River finally turned. He had a half-smile on his face, leftover amusement softening the annoyance.
That’s when he noticed Lamb.
For a fraction of a second, Lamb forgot to look away. Didn’t mask his expression. Didn’t sneer. Just looked.
River faltered. His smile froze halfway, his mouth parting slightly. His eyes went confused, but he didn’t look away. Stupid, reckless child, of course he didn't. And neither did Lamb.
The world went silent and still, and for that moment alone, Lamb looked and let himself be looked at. A weakness he already knew he’d regret, because Cartwright could be many things, but he wasn’t an idiot, no matter how much Lamb liked to claim otherwise. He would return to this moment, in the hours and nights to come, trying to understand Lamb’s gaze, trying to make sense of his own reaction to it.
And River being River, he wouldn’t let it go until it was too late.
Lamb blinked, and the moment collapsed.
He pushed off the doorframe, disgust settling back into place like a well-worn coat.
“What is this, a bloody knitting circle?” he barked, loud and ugly and safe. “If you’ve got time to squabble, you’ve got time to fuck off and make yourselves useful. Both of you.”
River straightened automatically. Shirley rolled her eyes. The world righted itself.
Lamb turned away, a cigarette already in his hand, lighting it as he headed for the stairs and his office. He could feel the kid's eyes on his back the entire time, and there was no denying the unmistakable sensation that he’d just fucked both himself and River without permission.