This side of himself had fallen under the throes of darkness to be illuminated by a moon-also a piece of himself, broken off to orbit. 

Unicron stretches out his senses in a concentrated effort to the moon.

And yes! 

He feels it!

Such a minor victory in the face of what he was once capable of! 

The moon is much smaller than his earthly self, and the sensors online quicker without a dense atmosphere or a constantly shifting mantle and crust. 

And Unicron feels tracks.

On the moon.

Small, impossibly small. And shaped similarly but different from a Cybertronian pede. His curiosity is maddening. So his creations are smaller than Cybertronians? But similar enough to have their own version of pedes? It makes sense, as their time as ‘The One’ saw them concoct a being that would serve as the base design for Cybertronians, and seemingly humanity too. 

And a bleached white flag decorates the moon. It’s so out of the ordinary from the otherwise inert lunar surface it’s like a flare in his awakening mind.

Humanity had reached the moon? 

Of its own volition?

Unicron’s subroutine records indicate humanity had only achieved flying machines in the past century and from that went to the moon?

Motion in the distance.

Nightfall is the same as if he was orbiting in a system with binary suns for all the difference it makes to his godly optics. 

A creature on a physically powered object approaches him.

And Unicron is still.

A constant gaseous exchange in and out from a miniscule intake.

Oxygen! 

It’s oxygen! 

A volatile, chaotic, explosive, damaging element, and it seems to be essential for this lifeform to live!

What a fiendish design! How utterly absurd! How it perplexes him that it delights him so!

In defiance of its own exhaustion it approaches on the two wheeled object, clearly of humanity’s creation. 

When it catches sight of Unicron it pauses. 

It has two, perfect little optics. Two tiny servo’s with five digits. From Unicron’s scans of it its own systems are a riot of microscopic, single-celled life that isn’t even of its own DNA!

It seems to be scared.

As Unicron watches it rallies itself, then continues on, neatly hopping off the two-wheeled creation, breathing heavily and approaching. 

With that single act, it shows more bravery and dignity in the face of possible death than many societies Unicron has vanquished. 

He shifts, and the entire earth rumbles. 

“You dare approach me in such an inconsiderate fashion?” 

It throws down the proto-altmode with such vigor it seems to be trying to match the noise Unicron had made. It…amuses him, greatly. To be mimicked by his creation. 

“Well, pops, apparently I get it from you! Cause Optimus says you’re our god and you want to kill us all! Now that's inconsiderate!”

Unicron had not bothered to imagine what a human’s first words would be to him. But to lay the blame at his pedes, to call him a hypocrite to his very visage? A being impossibly ancient compared to her, the thing she owes her life to, that as he gave it, he can take it away, and it speaks in such a manner? 

“Insanity!” He bellows!  “What foolish, irrational, stupefying, bravery!”

The human, whose little, pliable face had twisted in a coming rebuke of his initial adjectives, pauses in confusion at his last word. 

Never would he have thought it to make such a chaotic decision!

“How dare you!” Unicorn grits out, How dare it do something that appeals to his deepest, truest nature?! How dare it be enchantingly tiny? 

“And where is your cowardly Prime? Unbecoming to hide behind a creature so small!”

“Don’t you insult him!” It shouts, stomping its little pede and Unicron is nearly overcome with the urge to pick it up and squish its marvelously defiant intake. But to his surprise, not to the point of bringing actual harm to the creature. 

“You dare defend him?”

“He doesn’t know I'm here, none of them do! It’s why I took my stupid bike instead of the groundbridge or riding with Bulkhead.” It gestures to the two-wheeled object, or bike, as it says. 

Unicron is rendered speechless.

“...Cat got your tongue, huh?” 

Unicron does not know what a ‘cat’ or a ‘tongue’ is, but his mind is preoccupied.

“You defied the Prime you love so much, to come and see me?” That thought circulates in his head like the deep sea currents he had just discovered in his oceans. He’s so close to the surface now. 

“Don’t flatter yourself.” It grumbles, but it looks up at him with such curiosity. The unmistakable spark of sentience in its little liquid optics. It trembles, in fear, and from the cold of the desert at night. 

For one to be so small, but so brave. 

“...Why don’t you like us?” Its voice finally sounds as small as it actually is.

And Unicron finds that displeases him. 

“Don’t you dare to presume to know the feelings of a god, little one.” Unicron says.

It’s little head whips up towards him, colored filaments bobbing, little intake going round. 

Unicron steps forward and lets most of his mass drop until he is of a size similar to the Prime.

He stands over the human.

And does something he never thought he would.

He kneels down and presents his clawed servo.

The human is silent.

Then, steps on.

He brings it to his own optics and resolves to study it. It’s bipedal, mostly made of carbon, and water, with astoundingly complex internals. Its EM field has a small range, but it’s incredibly potent upon contact-a shame it can seem to feel it itself. 

Each tiny digit has its own nearly imperceptible patterns on it, loops, arches, whorls that fold like the layers of earth that make up its surface. 

“They’re called fingerprints.” It says quietly. It seems to be studying Unicron back and for the first time in eons he wonders of the opinion of another. What does it think of its creator? “Each human has a unique set of fingerprints. No one is the same.”

All unique? 

All distinct?

Their blood is tinted red due to iron, iron that made his very own energon take up its purplish tint in comparison with Primus’s blue hue. They breathe explosive air. They have a powerful acid in their internals to absorb all manner of energy because their little bodies, made of trillions of microorganisms, were constantly living and dying and fighting off invading organisms in a cacophony of organized chaos!

They hunger!

And their optics.

“Eyes. Mine are really dark because it blocks the harmful sunlight. But some are lighter brown, and some are blue, and gray, or hazel, or green, and I learned in health class that Albino’s have no pigment at all!” 

“Your ‘eyes’ have a black hole within their core.” 

Unicron’s dark spark had always been a hungry pit in comparison to Primus’ radiance. Primus’s children had each a piece of his radiance, to show in the way their optics glow, sending out light into the universe.

His humans had eyes, with a hungry little black hole in the center that greedily swallowed all light to see.

They experienced the universe as he did. 

They saw it as he did.

He is so moved by this that he goes from standing to kneeling as if to learn more by getting closer to this human.

No.

His human.

His humanity!

“What is your name?” Unicron asks his human. 

“Miko.” Miko seems tired. Miko seems to take after Solus’s frame type. 

“Miko.” he rumbles as a thunderstorm across his plains. Plains he can now feel.

 “You have not satisfied my curiosity, you have instead raised a tumultuous wave of inquisition! Ceaseless, deep curiosity to learn more!” More of his humanity! 

Oh, how he hungered, and his humans would understand that, wouldn’t they?

“Should the rest of humanity be as you are, I will stay my wrath.” Unicorn promises. 

“...Really?” It squeaks. 

The oddest thing happens.

It begins leaking corrosives from its optics! Salt! How horrendously rustful to Cybertronians! What a horrendous surprise! 

Unicron bears all of his thousands of denta in delight, and Miko bears her back, the ambitious tools used for their shared hungers.  

“Tell your Prime humanity is spared.”

“And the Autobots too?”

What a glorious, insolent creature! 

“They’ve been defending us from the Decepticons?” Miko peeps.

Hm. 

“I will be preoccupied with satisfying my hunger for knowledge by walking my earth. Should he stray from his duties he will know why it took all Thirteen of the Primes to defeat me, instead of a measly one.”

Unicron moves to set Miko down. He finds himself reluctant to part, and knowing now that humans were not out at night, gives her a weapon for defense.

“Dude, awesome!”

Unicron is also not sure what a ‘dude’ is, but he shall endeavor to find out. Nothing can escape his notice now. 

As Unicron prepares to depart he notices a tear in space-time.

Prime and his autobots rush through.

The Prime, Optimus as Miko had called him, transforms with such a frantic look in his optics, no doubt caused by his worry for Miko, that it further pleases Unicron enough to spare him.

“Miko! Are you okay?” The green one says. 

The Prime glares at Unicron. 

Unicron nearly rages at the insult to himself and shakes the earth so that a boulder falls onto the green one.

“Take heed, Optimus Prime!” Unicron spits. “I embark on my quest to learn more of my creations, a journey now with no ill-intent on my part towards them. But you?”

The autobots flinch to his great satisfaction, even from where the medic was helping the green one up.

“You all, the self-righteous creations of the god of creation and order, and who have yet destroyed said god, my dearly detested brother! You all dare pass judgement on me? On these humans yet still on a thriving world, the children of chaos who have not destroyed their own planet!”

The Cybertronians look stricken.

“You have come here to warn me from harming this humanity. Now I shall warn you! I now can see the galactic destruction you have wrought! I have an unbearable hunger to learn of my humanity, and I will see them safe from the likes of you so that it may be satisfied!” 

Unicron does not let them speak as the words of such mortals would bore him. 

He falls into himself.

And emerges again to explore his humanity.

(Ao3 link here where there is bonus content in the authors notes!)