<He seems like himself to me, just scared. I - think he is having trouble putting weight on his past self's assessment of my trustworthiness, which he does not actually remember, and I suspect he will be more comfortable once he has been in my head and confirmed it.> 

"Do you want morph now?" he asks Mhalir. 

"- Yes." How is that even a question. 

Leareth still doesn't technically have the codes for the morph cube, does Cayaldwin want to get Mhalir set up with that. 

"If you stay a little longer I can acquire you and actually have a Yeerk morph," Mhalir says to Essam.

"Sure."

Cayaldwin knows the codes for the morph cube.

Mhalir will get morph! And ask Essam to leave her host's ear for thirty seconds so he can acquire her! 

He looks around between Cayaldwin and Leareth. 

"- I want to go in your head first," he says to Cayaldwin. "If that is all right with you."

It feels - more informative, somehow, testing whether the Andalite scientist's mind and feelings are compatible with the story he's been offered. 

<Sure.>

"- Sorry, this is an unusually gruesome morph. I suppose you know that, since Leareth..." Mhalir sits down on the floor and starts morphing into Essam's Yeerk body. 

It's in fact a gruesome morph, but Leareth isn't especially sensitive to gruesomeness. 

Cayaldwin mostly doesn't care about things. He waits for Mhalir to finish morphing and then picks him up and holds him to his ear.

Mhalir spends a pointless moment being scared for no reason - though less than when he was in human form - and then slips in. His Yeerk brain mapped to a human body and then morphed Yeerk again seems to work okay; to the extent it feels off, that seems attributable to his overall confusion while he's adjusting to this. 

He spreads out into Cayaldwin's head, trying not to seize control, even though it's very very hard not to do so on instinct and he keeps doing it anyway and catching himself. Presumably the other Mhalir had a lot of practice Yeerking someone and then just being a passenger. He doesn't, not yet.

He drinks in Cayaldwin's thoughts and feelings and memories.

Mhalir is now also behind Cayaldwin's Thoughtsensing shield, which makes Leareth pointlessly anxious. Presumably Mhalir will just tell Cayaldwin if something is wrong, or leave his head and demorph. 

Cayaldwin's father is dead and this is, by far, the most important fact about the universe, with everything else colored by 'would be relevant if my father weren't dead' or 'irrelevant even if my father wasn't dead' or 'important to appreciating how bad it is that my father is dead'. They had worked together for twenty years, when his father was killed in combat, and he wishes it were him instead with an intensity only paralleled by his wishing there had been a backup. 

He'd been recovering, slowly, when they had been working on this before. He is not consciously aware of this, but there were patterns laid during their research together, pieces of what it'd be like to live in a world that didn't have his father in it. And then Mhalir died and it'd made it clear how stupid that was, and how pointless, and how fundamentally wrongheaded, he was guilty of trying to be all right and it was an atrociously stupid and evil thing to try to do. He isn't going to make that mistake again. Nothing matters and nothing ever will. 

He's not planning to kill Alloran, but this, too, is a throwing-away-of-meaning; trying to kill Alloran was meaningful and deciding not to is abandoning the idea that anything is meaningful or ought to be. Also it was very reassuring to expect to die, and it's a lot harder to do things while expecting to not die. 

Oh. 

He'd - guessed, a little, at how Cayaldwin's mind was shaped around his father, but this is about a hundred times as extreme as what he had been grasping at. 

He doesn't know what to say. Probably there isn't a right thing to say but he wants to say something. 

<I wish I could have met your father. I - wish I had ended the war twenty years earlier... I cannot undo the past. I am sorry.> 

He wonders if the other Mhalir said something like that as well. 

<This time I am not going anywhere. If something happens to my body then Leareth will fix it.> 

He tries to sift through the mountain of grief for a dead Andalite father, to figure out what Cayaldwin's feelings and intentions are toward him. 

Cayaldwin thinks that Mhalir is intelligent. It is approximately the only assessment he makes of people, that and whether they are annoying, and Mhalir is not annoying. When he's in better shape, like he was before Mhalir died, he also assesses whether they have worthwhile goals and whether they are too beholden to authority, and his opinion of Mhalir at the time was that he did have worthwhile goals now that he'd stopped having the stupid goal of defeating the Andalites in a war, and that he is not too beholden to authority. His assessment of Leareth is that he is intelligent and not annoying and has worthwhile goals and is not too beholden to authority, which is the highest available assessment. (Matirin, he thinks, has dumb goals, such as being popular, and is too beholden to authority though flexible about which authority and sometimes willing to substitute a metaphorical or abstract authority.)

Cayaldwin's intentions are to - do math? It's the only thing that's even slightly distracting from everything else. Probably at some point he'll die. He is not going to hurry it up but he does not feel any distress at the thought. Being alive when everything meaningful in the universe is gone forever kind of sucks.

...Well, it could be worse. Cayaldwin was at one point, before, in a better state than this, and maybe even on a slow but improving trajectory, and the only reason that stopped is because Mhalir died, and Mhalir is now effectively immortal. Even if Earth is destroyed somehow, Leareth has several backup copies hidden in secret on Velgarth, and Leareth comes back via another method...

<I should probably go talk to the other me> he says eventually. <I - feel less confused, now, but I had better get another opinion on whether I am all here. Do you mind if I do that from your head? I can also leave and demorph to do it, but I think you can enter text into the computer for me much faster than I could as a human.>

<I don't mind.>

Mhalir on the computer has been waiting for a while! He's had a couple of updates from Leareth that the first tries failed, but he keeps poking his clock and their next attempt should have been done at least an hour ago and he wants to know what happened! 

[We did it]

[You were disoriented but I think you're okay]

[You want to talk to you]

Mhalir can either instruct Cayaldwin on what he wants to enter into the computer, or he can just use Cayaldwin's tail without the relaying step, does Cayaldwin have a preference? 

Cayaldwin would rather enter it himself; he doesn't mind Leareth using his Gifts while a Yeerk in his head but someone using his tail is upsetting sort of the way suffocating would be.

That's entirely fine. 

Mhalir carefully describes his experience so far - the waking up bit-by-bit and disoriented and the ensuing period of confusion, the physical fear reaction of his human body, the difficulty retrieving memories from when he was uploaded. He feels pretty fine now. Going by the contents of Cayaldwin's head, everything is in fact as he was told - as they were told? - and he's a lot calmer as a result. He thinks he's intact? He's not sure if he would be able to notice anything missing from the inside, though. 

Mhalir in the computer has a number of questions for him! Some prompting for specific things he learned while uploaded, which computer-Mhalir can skim for in his notes, and cue the human Mhalir with enough context to help locate the memory but not enough to answer if he really can't remember. 

It takes effort sometimes, but he can remember everything eventually once prompted.