The question had apparently been on Tony’s mind for long enough that he felt he needed to defuse it first.
“Obviously,” he said, from the water, “the correct answer is that you become the literal Superman and spend your weekends dragging the world’s nuclear weapons into the sun.” He swirled his wine.
“Or possibly you spend the next decade identifying which alien civilizations have the most attractive residents and conduct an extensive survey in person.”
“That,” Leon said, “is your answer, not mine.”
“I’m painting a picture of the available options.
Come on — you don’t look remotely uncertain.
You know what you’re planning.
Tell me.”
“If I were you,” Tony continued, in the specific tone he used when he was making something up and being extremely sincere about it, “I would spend approximately one week dating every interesting person who’d said no to me in the previous decade, then fly to the outer solar system and see what’s out there.
Best case: alien beauties.
Worst case: still the outer solar system.”
Leon laughed.
He couldn’t help it.
This was, in fact, what Tony would do.
“I hate to tell you,” He said, “but the only alien life forms that genre convention suggests you’re likely to encounter at that range are facehuggers.”
“I’d take that chance.”
“You really would.” Leon shook his head.
“I’m not you.
I don’t have your specific ambitions.”
He leaned back against the pool edge, looking at the sky.
“I was the other Stark.
The younger one.
I went places and people were glad to see me because of who my family was.
The world was already showing me every courtesy it had available.” He paused.
“I’m stronger now.
None of that changes.
I have absolutely no interest in using what I have to take what I don’t need.
That’s not what this is.”
Tony looked at him from across the pool.
“That,” he said, “is very well said.”
The look in his eyes was the particular one — the one that meant my kid grew up right — and it was extremely visible.
“Tony,” Leon said, “if you keep looking at me like that, I’m going to find Pepper’s new slippers and do something with them that she will not approve of.”
“You’re being sensitive—”
“I’m your brother.
I am not a child-rearing success story.
Stop.”
Tony held up his glass.
“Let’s settle this the adult way.
Clink glasses.
Adults clink glasses.”
“Fine.” Leon clinked his glass.
“Although if you’re arguing that I’m too young to be considered an adult, that does raise some interesting questions about whether I can tell you what to do with your company.”
Tony’s expression flickered.
“I didn’t—”
“I haven’t finished what I was saying,” Leon said, pleasantly.
“About my plans.”
Tony redirected.
“Go ahead.”
“I’m not planning to change how I live.
Same as before.
But I am going to start taking a particular path.”
“What path.”
“Getting stronger.”
A silence.
“Leon.” Tony’s voice was careful.
“You already have enough strength to do anything you’d reasonably want to do.
Nothing in this world can stop you.
What exactly are you going to get stronger for?”
Leon smiled.
“Not now.
But someday there will be something.”
Tony accepted this without obvious enthusiasm.
“So…More sun?”
“Sun, yes.
But sunbathing has a ceiling and I’ve probably come close to it.” Leon turned the empty wine glass in his hands.
“I want to approach it from multiple directions.
Learn something about magic.
Learn something about bioenergy.
Develop my understanding of the relevant science.” He paused.
“And eventually — once I have enough of a foundation — I want to start from the most fundamental level.”
The moon’s reflection drifted slowly across the pool surface.
Leon lowered his hand into the water and closed it, feeling the resistance.
“Genetics,” he said.
“My own genetics.”
Tony was quiet for a moment.
“Like the super-soldier serum,” he said.
“Captain America’s enhancement.”
“Not exactly.
That would be irrelevant to me — the physiology is already different.
I want to study Kryptonian genetics specifically.” Leon looked at Tony.
Tony’s expression changed.
He set down his wine glass on the pool deck.
“I’ve been reading the comics,” he said, which was apparently a relevant thing to say.
“If I recall correctly the researchers who studied Kryptonian genetics at a serious level ended up producing Doomsday.”
Leon said nothing.
“A biological weapon,” Tony continued.
“Programmed at the genetic level for total destruction.
No capacity for anything else.
Not controllable by anyone, including the civilization that created it.” He met Leon’s eyes.
“Krypton made Doomsday, couldn’t stop it, and that’s the precedent for what happens when someone tries to push Kryptonian genetics past their natural parameters.”
“I know,” Leon said.
“Then you know this is not a simple road.” Tony’s voice had dropped from its usual register into something flatter and more direct.
“If Kryptonian genetics could be pushed that easily, every Kryptonian with a scientific background would have become a god.
They didn’t.
There are reasons for that.” He leaned forward.
“Leon.
I can work with you on a dozen other ways to get stronger.
You don’t have to go straight at the most dangerous possible starting point.”
“I’ll try other methods first,” Leon said.
“But I’m not taking genetics off the table.”
Tony put both hands in the water and then over his face and breathed for a moment.
He looked, Leon thought, watching him, exactly like a man trying to figure out how to finish a conversation he was losing with a man who had already made up his mind.
Tony Stark — who had created Ultron because no one had successfully talked him out of an idea he’d committed to, who had divided an entire alliance of heroes because he’d decided he was right and continued forward regardless — was now sitting in a swimming pool at midnight trying to talk Leon back from the edge.
Even Tony thinks this is too radical.
That actually meant something.
“Okay,” Leon said, eventually.
“I’ll admit it.
Going straight at Kryptonian gene research from the beginning is extreme.”
Tony let out a breath.
“However,” Leon added, “when I have access to kryptonite, I’m starting that research regardless.”
Tony’s eyes opened fully.
“Kryptonite,” he said.
“You mean the one thing on the periodic table that doesn’t exist in our world.”
“Our world, no.
The DC universe, yes.”
A long pause.
“I need you to say that again,” Tony said, “using words that mean the same thing but in a different order.”
“Remember my other ability that I told you before, I believe my Space-Time Leap ability can cross to other universes,” Leon said.
“Including the DC universe.
I haven’t tested it yet, but I have a strong sense that’s what it’s for.” He looked at Tony.
“When I get the kryptonite, I’ll give it to you.
Keep it somewhere accessible.”
“Why.”
“Because if the genetics research goes wrong and I become something I shouldn’t be — if I become Doomsday — you’ll be the one who has to deal with that.”
Tony stared at him.
Then he moved past that entire sentence entirely, because apparently there was a more urgent thing to address.
“You’re telling me,” Tony said slowly, “that there are alternate universes.
Actual, real, navigable alternate universes.
That you can travel to them.
That DC Comics is a documentary franchise.” He stopped.
“I need to know if you’re serious right now.”
“Completely serious.”
“Because theoretically — and I mean theoretically, the math is speculative — parallel universe structures are consistent with current quantum models, and I’ve done some thinking about the implications of—” Tony stopped himself.
“You’re serious.”
“Yes.”
“With this Space-Time Leap,” Tony said.
“You can go to other universes.”
“I believe so.
I haven’t done it yet.”
Tony looked at him with an expression Leon had seen exactly twice before, both times when Tony had encountered a problem that he couldn’t immediately classify.
“Leon,” Tony said, with some difficulty, “I remember you saying something on your birthday.
About what the bloodline activation unlocked.
Was that — was Space-Time Leap on that list?”
“It was the second thing mentioned.
Kryptonian bloodline, and then Space-Time Leap ability.”
Tony absorbed this.
“I may have,” he said carefully, “been so preoccupied with the first part that I didn’t retain the second part.”
Tony’s actual position, Leon reflected, had always been complicated.
He’d never fully committed to the “Kryptonian bloodline” framing — it didn’t fit his understanding of genetics or evolutionary biology, and he’d quietly filed it as “genetic mutation with solar sensitivity, mechanism unknown.” The evidence had eventually overridden that objection: heat vision, precision control, the punch that had detonated the garage.
Those were consistent patterns, not random mutation.
He’d updated his model.
But the Space-Time Leap ability had been mentioned once, on a day full of other information, and had apparently not made it into Tony’s working model of what Leon was.