Alec is fine, really - it's almost enough just to be physically himself again. And a version of himself he's never been before, one with the ability to make his own choices. It's practically inconsequential that he is, at least for the forseeable future, tied to a wheelchair. Really it's a wonder most of his body survived at all, and he's been humbled enough over the past few years to be able to leave a gift horse unexamined.
He may have just lived through the ego-death to end all ego-deaths, but it's almost easier to let go of things when it's literally the entirety of your life that's in ruins; a clean break. Hell of a lot easier than watching his friends die around him slowly, one by one.
Now his only tether to his childhood, to Plectum, is Tump.

Tump is the first face he sees leaning over him when he wakes up in hospital after all of it, with a smile on his face that Alec hasn't seen in a decade. Tump's friends still aren't so keen on him, but they suffer his presence in their lives as Tump's pet project. Some of them pity him, while others barely spare him a glance now he's no longer capable of harming them. At the end of the day, for some goddamned reason he is allowed to sit in on their get-togethers. It doesn't escape him that the fact they never forget to set a place at the table for him  makes them far more gracious than he would have been in their place.
It's almost... nice. Safe, which in itself is a novelty to him. The pain is even tolerable, especially in comparison to the first two decades of his life.

And still, Alec has no desire whatsoever to actually become a part of the group. He is perfectly satisfied thinking of himself as a dead end, gone so far that returning were as tedious as go o'er. There is no more pleasing shape that he could contort his personality into for them with all the baggage he has accumulated in his relatively short life, so he might as well hunker down and wait for death where he is now. He tells Tump this, but he only laughs, awkwardly.

Whether he has decided to ignore Alec's explanation or simply disbelieved him, Tump does his best to involve him in is and his friends' lives, in the beginning going so far as to convince them all to hold their little meet-ups in his hospital room. Being his unwilling charge also entails being brought to and from physical therapy, having lunch together, and being read to like a child. It's what cacti must feel like being overwatered by well meaning idiots, he thinks, and all it accomplishes is making him snappish.
Before the first month is out, what he yearns for more than anything is to have the strength to just get up and walk out on him. But after years of abuse and disuse, Alec's muscles are weak to the point that sitting up for longer than an hour or two has him fatigued enough to need a nap, so that is decidedly not an option.

It cannot be said that Tump did not fit in with his fellow CIECE members - he knows exactly how to talk Alec into inadvertently agreeing to move in with him when he's discharged. It's not like he's really got a choice; he can't manage on his own and has no family to speak of. This is the objectively best option for him, but selfishly he cannot help but hang onto a bit of resentment over it.
The place Tump has picked prides itself on its accessibility, and it may well be accessible for people strong enough to turn their own wheels. But within about half a year, Alec has only just accomplished the massive task of holding his back straight in his chair for the better part of the day, which means that while the fixtures in the bathroom are a welcome relief from needing a nurse's help for every little thing, the threshhold of the front door is an unsurmountable obstacle to him.

Meanly he sometimes thinks Tump is happy to have him so helpless. Few things seem to make him happier than sitting Alec up and brushing through his grown out hair like a doll's. And for as much as it irks him, he needs the human contact badly.

One or two times he finds himself falling asleep while gentle fingers trail over his scalp, waking up hours later on the couch with a blanket draped over him and his chair beside him.
The worst part is that he can't feed himself. By now he's able to lift a fork, sure, but he can neither reach the kitchen sink nor the cabinets above the worktop. Even being taken for regular walks he can deal with, but it sets his blood boiling every time Tump takes yet another plate he didn't manage to clear out of his lap with that little concerned frown on his face.

As all habits do, it starts with just one contextually innocent incident, which ends up with Tump tiredly hauling him into his own bed at half past two in the morning and slumping down on the mattress next to him. After that, a prescedent has been set and it becomes a more and more frequent occurrence. Alec doesn't dare ask what has Tump clinging to him like this, but he takes what he can get, greedy to take up all the space the fool will let him. He doesn't ask much in general, and Tump doesn't volunteer his thoughts often either except to nag him about what he ought to be doing.
For all that he came out of the whole mess the tragic hero with both feet planted firmly on the moral high ground, there's no denying it has changed him, and for the worse.
Alec derives a grim satisfaction from not being the only fucked up one - while Tump puts on a great show for everyone else, the walls can't be up every hour of every day. And he is there to observe the low points everytime - even if not by choice.

And so they get closer, pretending not to see each other's cracks in the façade.

Soon, Tump's hand rests on his shoulder on the train, his lips touch the top of Alec's hair once he has finished tying it back, he falls asleep on Alec after coming home from drinking with his friends. The more he thinks about it (and boy does he have time to think), the more obvious their shifting dynamic seems: they started down this path years ago, and by the time they restarted Alec's heart in the ambulence it had been set in stone. Tump is all he has, and although Tump has a whole life out there - friends, a cause, a job - Alec seems to be the only thing he feels comfortable reaching for.

They escalate one rainy thursday when Tump comes home drenched and grumbling, and heads straight to the shower. He finds Alec there, head awkwardly laid back in an attempt to wash his own hair, and suddenly, he's angry. Whether he's angry at him denying Tump the chance to do it, or at the attempt to gain just a sliver of agency, Alec has no idea, but it's infectuous either way. When Tump leans down to snarl in his face, he grabs him by the collar and crudely bites his lip so hard he draws blood. For whatever reason - it stays unexamined in the moment - Tump takes it as a kiss. He doesn't mean it that way; it's just that snapping his teeth at him is the only thing he can actually manage short of headbutting. Or so Alec tells himself. His already wet hair does not get washed that day.

The tension in the apartment becomes tangible after the incident. It's not the pleasant kind of tension. Alec stops sleeping with his back to Tump, and Tump's eyes seem to follow him around the apartment where ever he goes. The friend group picks up on it, which for the first time makes him feel downright unwelcome in their midst.

When he refuses to come along to a get together for the first time since he physically wasn't up for it, all Tump does is give him an assessing look and nod. Although it takes him months to figure out why, that makes a cold shiver run down Alec's spine.

It comes to him while he's half-laying on the kitchen counter - his legs are useless, so he has to brace his whole torso against the laminate to be able to reach up and into the cabinet. It's that he has stopped trying to make Alec not entirely reliant on him. In fact, from then on he seems to delight in it more and more.

In 'forgetting' to feed him to force Alec to come begging, in casually pushing his chair aside as he passes, in not telling him their upcoming plans anymore.
It's like he's suddenly found himself at the bottom of a well wondering why he climbed down. It's not overt until he sees the pattern; just negligence, just inattention. Alec gives back as good as he gets, makes a mountain out of every mole hill in his path and refusing to do little common courtesy things like hang up a clean towel. Just little things, annoying things that could be chalked up to carelessness.
Whenever Tump touches him it feels like he is gripping too hard, trying to mold him into the shape he wants him to be, and so Alec doubles down on his blank accusing stares in retaliation - they're a talent of his and especially unnerving since Tump can't escape them in his own home.

It's a mistake. After a few weeks of this dance, Tump stops talking to him or even really looking at him. When he needs to convey something, his hard eyes drift to somewhere over Alec's shoulder and he speaks in short, clipped commands.
Because he's miscalculated. At some point - probably months back and like an idiot he just didn't notice - they passed a point of no return after which Tump started disengaging. Now it's only him desperately hanging on, while his other half has realized that the entirety of his life does not have to happen in this awful little apartment.
It's probably his own fault in a very direct way: he's the reason Tump started staying out longer out of spite. He always assumed they were as miserable as each other, but this? He's already played all his cards. Tump is his entire life and Tump hates him.

It's so clear in retrospect he could kick himself. Except of course, that he can't, and that he wouldn't if he could, because he'd be running for the hills already.
Alec becomes too scared to sleep at night. Instead, he takes advantage of the few hours Tump is out for work or meetings with friends - to which he's never invited anymore. Do they wonder what happened to him?

The downward spiral leads him steadly to its natural conclusion: The only way to come out on top is to strike first. He contemplates what he has to do for a week, barely able to distract himself from it, the tremor in his hands so obvious even Tump seems to take notice. That narrows his time window. He has to act before, before-

It's a day like any other. They don't eat together anymore, and thank god for that because Alec is so nervous he surely wouldn't be able to choke anything down. But he cannot not watch.

When Tump starts coughing and sputtering, he looks up through teary eyes and sees the truth in whatever Alec's face is doing immediately. Unsteady on his feet he lunges for him in a rage, but his target is prepared to dodge, his muscles twitching with anticipation of this moment. He doesn't get away far enough fast enough before Tump's shaking hand closes around the footrest of his chair and hauls it up, sending Alec spilling to the floor in a limp heap. He gets in only one or two kicks before doubling over in pain, and from then on Tump is too occupied spewing up his guts to bother with Alec.
He sits there on the ground, watching, staring, until long after the horror show is over. His eyes are fixed on his friend's unruly mob of hair sprawling over the kitchen tile. He thinks he should be horrified, but he's just hollowed out. Killing was different in the system, more satisfying and less... unsettling.

Picking himself up off the floor hardly seems worth the effort, but after what is probably hours he does manage to drag himself onto the sofa. He leaves his chair behind in the kitchen, since chair or no chair, he's trapped himself. There is no going back from this, and there is no way he'd make it out of the front door. But at least his whole world is with him in the awful little apartment.