It was Águila who first pushed for the testing to become more aggressive.

Her logic would persuade the researchers; first she used it to win over Sueño: "The sooner they solve the Immortality Problem, the sooner we'll be allowed out of here."

Sueño took the argument to the next level: "There's two of us. Two test subjects. That's a beneficial redundancy. Worst case scenario, you destroy one, and have a spare."

Águila helped her refine that argument to language that would persuade the project manager, Lyric, and not freak her out.

"Every day that passes without resolving the animus crisis, the cap on immortal sous prevents families from being able to have children. Mothers fade to mortality. Potential parens choose sterility. Don't allow the passing centuries to make you forget the urgency." Lyric was over four hundred, though she looked like what used to be called middle age — a nonsensical term now because there's no middle in eternity. The skin on her face sunworn and mature, though her wrinkles were magiced smooth, and she was slim with the movements of a wise old body. "Even if one of us were to tragically give up our lives to the cause, you would retain a second test subject. A backup."

The key to the animus cap had to be found within the impossible twins. Somehow, their parens died to make two babies live forever; aer one animus became two. Somehow their parens died bringing twins into the world without surrogate animuses. An animus split in two to be shared equally between sisters.

None of the Constellation researchers could explain how an animus could be divided. And the girls heard the researchers whisper.

"Why two? Why has this occurred in natural gestation only? Why have twins been allowed conception only once in recorded magical history?"

They couldn't understand it because they had another theory, one that made more sense. "Infinity divided by anything is infinity. We can't determine why an animus divided into only two — because if we could split one animus apart, it should split infinitely."

"Nature and magic split one animus apart into just two. Why two and no more?"

"An infinite life created by fusing a mortal soul with the infinite power of the multiverse should be possible to split into an infinite number of animae — because infinity divided by anything is infinity."

"How do you divide infinity in two?"

Their testing consisted of poking and prodding at Sueño's animus, and then Águila's, and back again, testing for some place to split the soul into two as their madre's had done.

"Why can't we replicate it artificially in vivo?"

"Doesn't seem anywhere to split the animus in half."

So the girls pushed the scientists to attempt to divide one of their animae by infinity.

Their argument was strong, as was their cause. When they presented it to Lyric, they took turns, Águila speaking first. "It takes one life — the life of the parens — to fuel an immortal life, and for the past three millennia we have circumvented the process for most, or those who can afford it anyway, by selling the animae of the dead. Every Soliari in the empire who dies has their animus reclaimed and reused. A fetus can be infused with immortality before the child drains the eternal life force of the parens.

"Wonderful, but with an immortal population, there are only so many deaths a year," said Sueño, picking up the thread. "Only so many animae in the pool. Millions of Soliari want to have children, but the average death rate per annum is in the low hundreds. A thousand deaths a year would allow a thousand births. One to one. But then Sueño and I were born, and the equation changed. Two to one ain't bad. It's an improvement. If one animus could be split in two, we could double the birth rate. But the leading theory — the only compelling theory in my mind — states that theoretically one immortal soul should be capable of dividing infinitely."

Águila took over again. "If we could divide one animus with immortal life into an infinite number of animae, we could fuel every immortal birth for the rest of time. No parens would ever die to give their immortal child life again; no more death penalties to increase the reproduction cap; no more centuries on the reproduction waitlist. We can solve the crisis."

She concluded, "All we have to do is divide my animus into an infinite pool."

They didn't choose Águila, though. Not to go first. It shouldn't matter much, who went first, but they chose Sueño out of a hat or something, to randomize the study, they said. Remove any bias or researchers' impact.

The experiment to attempt to divide Sueño's animus infinitely had been the only time Águila ever felt the twins' intuition as described. In theory, Lyric had promised, Sueño should be able to keep one of the infinite pieces of her animus inside her body.

Her animus could be divided infinitely, with one spirit residing within her. The rest would be sent to a conduit reservoir of Constellation animae.

Águila had truly felt her sister's spirit blaze with the fire of potential for an unending stream of lives, of beings with whole worlds of possibility. The alternative realities flared within the girl for a flash of a moment.

Then sputtered out to cold nothing.

Infinite souls newly created by Constellation researchers died in that moment, and so did Sueño, a young woman who seemed to shrink immediately, though it was impossible, back into a small girl, wrapped in a white coat, with red strappy dancing shoes on her feet.

That had been eighty-two years ago. After Sueño died, Águila never asked to leave the confines of her test tube world again. The engineers taught her magic. When she progressed to advanced theoretical magic, professors from Magicians' College linked to the lab to instruct her. Within a few short decades, Águila became an engineer herself, and the forefront head expert on the Immortality Problem. At least, if you asked her.

Lyric felt differently. "No, you can't run your own experiment. You're the test subject. That would be like a surgeon who operates on aerself."

Águila wanted to run the infinity division experiment again. To fix the painful consequences of eternal life, and to make up for Sueño's loss. So her death would not be for nothing. "I discovered the flaw. Trying to leave one piece of the soul in the body. It can't work that way. This procedure is entirely different from what happened when Sueño and I were conceived, but our conception showed it's possible. We need to do it again, but this time, reclaim every animus, including mine."

"We're not running your own schema on you. It defies scientific objectivity."

The obvious go-around would be to claim it wasn't Águila's project at all. It was Cadence's.

Cadence did not like the plan. The one Águila had told her about just over an hour ago now. No matter how much Águila begged and pleaded, aer refusal was constant.

"And why should it be you?" the debate went. "If the experiment has nothing to do with how your parens' animus divided into two, we could take test subjects from anywhere. Death row, for example. Criminals awaiting execution could provide our subject of experimentation, we don't need you for this. Your specialness has nothing to do with it. Maybe that's why Sueño died. What made her special has nothing to do with this division method, so it offered her no protection. If you want to try to divide an animus infinitely again, then use the animae reclamation pool for your experiment, the incoming souls sentenced to die. I'll sign off on it."

Why should it be me? Águila wrote in her documentation. Well, unlike convicted criminals on death row, awaiting execution so some Constellation executive can welcome a bundle of joy home, I have been a test subject my entire life. From the moment my heartbeat was detected next to Sueño's, or hers next to mine, it's been my path. It's been my responsibility to solve the problem. I didn't choose that responsibility. It was thrust upon me. And Sueño too. Constellation didn't give us a choice, and its president, Julia Mars, never even asked us what we wanted.

I never got a choice other than living my life inside a test tube. No one ever asked if I wanted to be subject to magical testing from morning until night every day from my youngest memory. When my sister asked to leave, she was told she didn't have a choice. My sister was killed for this research.

Only now am I given a choice — to subject others to my fate in my stead. To force a destiny upon them without giving them any option. No, that's not what I'm going to do. I've formulated a solution; I've recorded my hypothesis, verified my methodology, devised a proof for the theoretical mathematics behind my theory. Sueño was killed beneath the gnomon of the Constellation star dial, but if my formulation is right, I will share in her destiny — only it will be for something. I will die for the rest of humanity to live forever. What more could a Soliari ask for?

Águila allowed Cadence to read over the documentation. And that was the final argument needed to persuade aer.

Aeh loaded up Águila's program, connected Águila to the star dial, the router that connected all Solari magic to the source — all of the stars in the multiverse.

Cadence let the tears come while initializing the program. Águila did not. For an infinite yet singular moment, Águila could feel not only every particle that made up her body, but every infinite division of the soul inside her — the immortal people, simultaneously individual and massive, who would come to exist for all the rest of time. She could feel each one of them, their conception, their thoughts, their speech, a whole lifetime of mornings, and woes, and fears, tears and stories, every sensation of every moment of their lives, and she could see the future history of the rest of time. With that foresight came the certainty that it had worked. The Immortality Problem had been solved. Every new immortal that came into being would come from her. Every Soliara child for the rest of time would be her daughter or son.

President Mars would announce the success of her office, claim victory and offer an animus to every parens on the waitlist, to every person who wanted to experience bringing a child into the world.

Only Águila saw, simultaneously, infinite other . . . possibilities. In a multiverse that extended on and on, branching into alternative realities, were other timelines, other outcomes.

President Mars chose differently in some of them.

With an infinite pool of souls with which to fuel immortality, Mars would sometimes choose artificial scarcity, to constrain the supply. To lie to the people and tell them that the reproduction cap remained a necessity and only permit the surrogate animus program's infinite supply to benefit those who could pay the highest price.

In some of them, Cadence's grief led to a similar outcome. Aeh wanted to punish Constellation, its executives and the upper strata who had always been the first to benefit from the animus pool, who wanted to solve the crisis so badly they drove Águila to her death. Cadence would sabotage the reservoir in some of them.

In others, it was a simple technician's mistake that failed to transfer Águila's infinite souls into the conduit, and at the same time botched her schema so it couldn't be replicated, just because bad luck always struck two times, or more.

Or an engineer whose breakthrough in expanding the reservoir to an infinite capacity simply failed this time.

Or a connector to the Star Dial failed at a critical moment.

Greed, human error, revenge, bad luck, mistakes, in infinite possibilities. Instead of peace, Águila's animus on the moment of the end of her life experienced the totality of human experience. All for nothing, all for everything.

I hope Aguila's Star Episode I was a good time! Ahah, I feel this story got a little off the rails, so, dear ones, more than ever your honest thoughts and questions would be very much appreciated! How believable were Aguila's motivations? Did this whole thing make any sense? Ahaha. I appreciate you, friends and readers. And as always I appreciate any stars you have to spare today <3

I'm releasing another story today because I had time to revise one that's been sitting in a desk drawer (so to speak) for a little while, so without further ado, I present to you, Yue's Star Part I!