Chapter Text
Tony always had the best toys. Without his equipment the series of genetic analysis Bruce had completed in a week would have taken years with a full team working on it, and even then he doubted they'd have discovered the anomaly. It probably didn't mean anything. Even though that gene sequence was... odd... well, evolution is a process of mutation, and most mutations cause so little change they don't matter. And really, if it was going to be a health problem, it would have shown up by now.
Everyone else had checked out as expected. His and Steve's cell structures were complicated because of the treatments they'd undergone, but explainable within that context. Thor's alien DNA was, well, alien, but the differences lay more in lack of flaws than anything else. Natasha and Clint were simply extraordinary people.
The sequencer beeped again. Another anomaly? Multiple mutations are rare. Another beep. Bruce took off his glasses and rubbed the bridge of his nose even as the sequencer gave another alert. Ok. Great. Tony was going to be down in the lab any minute, poking at him to come play Team Science. "Jarvis!"
"Yes, Dr. Banner?"
"Collate anomalous gene sequences from the on-going analysis, identify origin." Bruce turned off the alert sound, but let the display continue highlighting anomalies. There were a lot of them.
"Origin has been determined," Jarvis said, a few minutes later. "Anomalous sequences are consistent with Felis silvestris catus."
"Cat? Who's getting a cat?"
Bruce jumped at the unexpected voice. "Oh! Hi, Tony." He had never thought about it before, but Tony's ability to pad up soundlessly... no, no, Tony is not a cat. he's just... he has a little genetic anomaly.
"I should have put a no pets clause in the lease. Oh, yeah, I forgot to have you guys sign a lease." Tony got into Bruce's space, leaning against him to poke curiously at the holo display. "Huh. that's... weird. Isn't it? I mean, biology's not really my thing, but... why does this file have my name on it?"
Bruce cleared his throat. "Um."
Tony tilted his sunglasses down his nose and looked at Bruce, who couldn't help imagining that Tony's mustache was twitching like a cat's whiskers. "Very informative. Got bored and decided to run some mad scientist simulations? You should have called me. I used to play El-Fish. Kinda hypnotic, watching weird fish swim."
"Ah. It's not a simulation."
"But it has my name on it." Tony stared at the display, where Jarvis had now helpfully labeled all the non-human sequences as catus. "So... It's a joke? Yeah. Good one, Bruce." Tony grinned. "Pull that one on Legolas, paste in some bird genes... what... well, I think It's funny. Why aren't you laughing?"
"Because it's not a joke. You're transgenic."
"Damn." Tony looked at his hands, and then patted his chest. "I don't feel any different. I wonder which magic-using idiot did it and what it'll take to get them to reverse it. Have to pull up the mission files and see..."
"Tony. This didn't just happen, and it's not something you can undo." Bruce felt very bad about this. Tony looked like he was on the edge of panic and holding it off by denial. "It's you and it's the way you were born."
"Look, that's impossible. No one, and I mean no one, had the technology to even begin to attempt gene-splicing back then. Hell, they hadn't even managed to use a horsehair to split a frog egg to clone it! Not that I'd put it past dad to have tried but he didn't have the tools!"
Bruce had been thinking about that, and while he didn't like it, he had an answer. "He had the Tesseract."
"Fuck." Tony stared at Bruce for a few more seconds, then turned and, well, fled.
"That didn't go so well." Bruce said.
***
Tony came back an hour later, smelling more than a little of whiskey. "Did you tell anyone?"
"No." Bruce turned to face Tony. "I wouldn't, you should know that."
"Yeah. I should. Cat, huh. Could be worse. What if dad had a lab rat handy?"
"We don't know that it was deliberate," Bruce said carefully. "I mean, really, we don't understand the Tesseract today. It might have just been... proximity, if your family had a pet cat and your mother helped with experiments. He may never have known what happened."
"My dad called me 'his greatest creation'. And we never had any pets. I remember once asking if I could have a cage bird or goldfish. He damn near choked on his drink. Yeah. He knew."
"I read about your father. He'd worked on the Manhattan project. Maybe he was afraid his genes had been damaged, and he was trying to use the Tesseract to make sure you'd be healthy."
"Why use a cat to patch in flawed sequences? He could have borrowed some patriotic young soldier for an experiment. Cap isn't the only selfless idealist in uniform, not even these days."
"I... have no answer for that."
"Hey, on the bright side, I don't have a tail or claws! I can pass for human!"
"Yeah. that's convenient, isn't it."
"Oh, yeah, no. Don't get all sad-face on me, Bruce. You're the most humane and human guy on the team." Tony held out a bag of dried fruit. "C'mon, let's play Mad Scientist."
Bruce smiled and accepted the offering. Do not think of a cat laying a 'present' on the doorstep. Dried papaya is not the same as dead mouse. Tony is not a cat. "Ok. I've been looking at your medical records. What there are... didn't you ever have a full medical done?"
"Nah. I was never sick, so why waste the time?"
"That is the point of a full medical, having a baseline to judge when you are sick." Bruce shook his head. "Your body temperature is 99.8, which is in the high range, but it's not particularly unusual. What is unusual is that you have an extra thoracic vertebrae, and two more lumbar vertebrae, which makes you more flexible than most people."
Tony grinned. "And that has come in handy."
"I don't really want to hear about your tom-catting around, Tony..." Bruce closed his eyes. "Oh, God, I didn't say that, did I?"
"Yes, yes you did. And I am deeply, deeply insulted." And then Tony laughed. Maybe the laugh was brittle, but it was a good effort. "And very, very grateful I don't have feline anatomy down there. I'm pretty sure I would have noticed that."
Bruce was becoming interested in the puzzle as a puzzle. "There are a lot of patches, but none of them affected your external appearance. That seems statistically unlikely."
"Which lends further credence to the idea that it was deliberate."
"Probably. Jarvis has drawn up a list of tests we can do here."
"Multiple choice?"
"That would be cheating."
***
"Well," Bruce said several hours later, "your senses appear to be human normal, but your digestion is slightly skewed. Wheatgrass smoothies and cheeseburgers are good for you, but you should consider arginine and taurine supplements. Chocolate is toxic, so are large amounts of onion and garlic."
"Never could get past the smell of any of them."
"You're lucky you can tolerate caffeine and alcohol." Bruce turned back to the test results.
"Bruce, why do you say such horrible things?"
"Because if I'm too nice to you, you become unbearable."
"A world without caffeine would be unbearable." Tony picked up a cup of coffee and held it to his chest. "My preccciiiouss."
Bruce looked at Tony seriously. "No common medicines are toxic, which is great again, since the first time you took something for a hangover would have probably killed you otherwise. Oh, remember, never, under any circumstances, eat philodendrons or drink antifreeze."
"You're starting to enjoy this, aren't you?"
Bruce grinned. "Maybe just a little. Can you move your ears independently of each other?"
"I refuse to answer that question, as it lacks dignity."
"So, that's a yes." Another check box. "Your tolerance for heat is very high, and you can survive on very little water. It's quite possible you can even rehydrate safely by drinking seawater."
Tony gulped more coffee. "Yeah. Deserts aren't my favorite place, though. They're very boring after the third or fourth day. And sand gets everywhere."
"Well, anyway, that's the high spots. So...are you all right with this?"
"Sure, I'm fine. It was not as if it changed anything. Actually, I'm glad I found out. I was considering, well, in a weak moment thinking it might not be so bad, becoming a father. Can you imagine? I mean, I'd be the world's crappiest dad, anyway, but... this... yeah, thanks Bruce. You saved me from making a really huge mistake." Tony put on a big, photo-opportunity, grin and stood up. "Let's have pizza tonight. I feel like anchovies. Fish is good. Right? "
***
Why was he getting thrown out of a window without his suit, again? Tony thought before instinct took over and all thought was subvocal, mostly math, angles and calculation, too quicksilver fast for words. He twisted his legs and back to flip himself to orient level with the horizon, then spread out his arms and legs and arched his neck and back while relaxing all his muscles, like a flying squirrel. Once he realized what the villain had in mind, he'd run across the office and angled to aim for a window directly above a canopy. Terminal velocity for a human was generally around 120 mph, and twelve stories was certainly far enough to achieve that, but proper positioning should slow him down to under 100. His internal time sense was excellent, he didn't need to look down to see when the time had come to change his stance to minimize impact damage. His knees bent to get under his center of gravity, toes pointed down so the balls of his feet would hit first, his arms wrapped around his head with his fingers locked behind. And then he hit the canopy, and heard it tearing, but he was already rolling, tucked and calculated to get two more rotations before hitting the small patch of close-trimmed grass and then rolling and ...
"Ow." Tony blinked and cautiously took his hands from his head and did a quick inventory. No bones sticking out, check. Vision blurred, but adequate, check. Screaming, but not him making the noise, check. He put his hands down on gritty cement, got his legs under him, and staggered upright. Pain, check. "Ow." Something really big and green stood in front of him, smelling like sweat and that weird fermented cabbage that Bruce liked. Tony blinked again. Things were still blurry, but he'd recognize that shade of green anywhere. It was comforting, like shade trees in summer. "Hi, big guy."
Tony staggered close enough to wrap his arms around one of the Hulk's legs. "Sorry I couldn't wait for you." And then standing up, even while holding onto the Hulk, was just too much trouble, so he slid down to sit on the Hulk's foot. It was warm, and he closed his eyes and leaned his cheek against equally warm shin. It felt good against the massive ache that was his whole body right down to his hair. The Hulk grumbled something, but he didn't move, didn't try to make Tony move, so that was fine.
After a while, not long, not long enough, because he was just getting comfortable, well, had optimized the arrangement so pressure was on the parts that hurt marginally less, there was noise disturbing him. Noise. Voices. And the Hulk rumbling back. Someone was arguing with the Hulk? That degree of stupid deserved an audience. Tony opened his eyes. Yay. His team was there. He counted them twice because there seemed to be two of each of them.
"Oh. Hi guys. Did you catch the baddie?" Tony thought perhaps he should be more specific, but It was all a bit of a blur of shouting and spandex in colors not meant to go together and he wasn't quite sure who threw him out the window. Why do villains never wear Armani? Show a little class. "Hey, Cap, you don't look so good. What's wrong?"
"Tony... you fell twelve stories." Steve was white-faced and his eyes were huge. He must have been really upset, because he was holding the bad-taste spandex villain by the throat, and then tossed him to Thor without looking to see how he landed. Tony thought he heard Steve whisper 'Bucky', but maybe it was 'Lucky'.
"Well, technically it was a bit less than eleven... because of the balcony. Can we go home? I want to bathe in a tub of Tiger Balm." Why were they all staring at him. Even Clint was actually looking worried, and he didn't think Clint even had a worried face.
Steve moved forward and laid his hand on Tony's shoulder. "You're going straight to the hospital."
"No. Don't like hospitals. They're cold." Tony rubbed his cheek against the Hulk's leg.
"Yes," Natasha said, "hospitals are always cold."
Tony blinked at her. "You agree with me, that's a first, isn't it?"
Natasha gave him her patented, 'you are an idiot' look. "I have already called for an ambulance. When it arrives you will be on it. Whether or not you're conscious will be up to you."
"No jabbing me in the neck. I hate that." The big green leg shifted and began shrinking. Tony was annoyed to find himself tipping backward until he was lying on the ground looking up at Bruce. "Don't let Natasha jab me in the neck, Bruce. No hospital."
"You have to, Tony." Bruce knelt down beside him. "You could have internal injuries."
Tony felt a cold shiver run down his spine. "No. No operations."
"Only if it's necessary," Bruce said in a soothing voice, like someone dealing with an unreasonable case of hysterics.
He grabbed Bruce's arm. "You don't. No. I woke up. In the cave. His hands... in my chest." Tony hauled himself to his feet, terror lending him strength. "No hospital!"
"Oh, hell." Bruce got up and wrapped his arms around Tony. The rest of the team was standing all around, there was no way for Tony to escape, even if he could run. "They didn't know. They used the wrong anesthetic. Listen, Tony, I'll make sure that doesn't happen. I'll bring in... a specialist. I'll explain. It'll be all right."
"Explain what? What have you been keeping from us?" And that was Steve's leader voice and worse, it was his 'my feelings are hurt', voice.
Tony leaned his head against Bruce's shoulder. "Fuck. Tell them." He didn't want to look, to see their reactions.
"Um," Bruce said. "A few weeks ago, I ran genetic scans on all of us. I meant to just use Tony, Natasha and Clint as controls to compare with Steve, Thor and me, but Tony's results showed prenatal transgenic tampering. That's why he was able to survive that fall, but it also makes medical treatment more complicated."
Steve frowned. "What?"
Tony muttered into Bruce's warm skin, "I'm part cat." He was pretty sure he could have come up with a better way of saying that, but he just wanted it all over with and to be back in his own bed with the lights off and the covers pulled up warm. And then everyone was talking, and there was the sound of a vehicle approaching, an ambulance, the little part at the back of his mind that recognizes engines told him, and really it was too much trouble to pay attention to everything, so he just held onto Bruce and tried to trust him and not think about cold, damp miserable caves and how much it hurts when the cold goes right into your open body. He never, ever, liked being cold.
***
S.H.I.E.L.D. doctors were used to the unusual, so when Dr. Arnold Plotnick arrived in a Stark helicopter piloted by Agent Barton and they were told he'd be consulting on all aspects of Mr. Stark's treatment, and would have to sign off on all medications, anesthetics, diet and even topical applications, no one batted an eye, although one nurse did ask why he had a toy mouse poking out of the pocket of his lab coat.
***
Steve looked in the open doorway. The room was dark, barely lit by the glow of Tony's arc reactor. Tony was snoring, but it was an odd sort of thrumming, rhythmic sound. "Tony?" Steve called softly. They'd brought him back to the Tower a lot sooner than the doctors had liked, but Bruce had pointed out that the longer he stayed, the more likely someone was to get curious and start asking questions and that... just couldn't end well. So Tony was back in his room at the Tower, with a whole list of instructions for the care-givers. Tony had kicked Dr. Plotnick out of the room after the unfortunate remark about Elizabethan collars, but Steve thought the man was only joking. Maybe. Tony had been using his teeth on the casts on his forearms, but that was only because the edges were ragged and irritating his wrists.
"You awake?" Steve asked.
"I am now." Tony sounded odd. He was still making the humming noise, but softer.
Steve blinked. Above the reactor glowed two round spots of golden eyeshine. That... yeah, ok. "It's time for your pills. I need to turn the light on."
"Yeah. Jarvis, lights." Tony looked at Steve. His pupils were huge, but as he blinked they rapidly shrank to normal. He sat up, clumsily. "I hate casts. Why did I have to break both arms?"
"I think the concrete had something to do with that." Steve brought in a tray with the pills, water glass and mug of tea. "Anyway, it's only hairline fractures. You'll be back in your shiny suit in a month or so."
Tony rubbed at the side of his face with his left cast. "This is so awkward, I'd cut my throat shaving. My goatee is going to go to hell." He scowled down at the casts. "Hey! How come no one's written any smartass comments on them? I feel unloved."
"No one felt like making jokes. You almost died."
"Yeah. Well, I guess I still have a few of my nine lives left."
Steve didn't know what kind of expression his face made at that remark, but it was enough to make Tony look away from him. "Tony..."
"Just give me the pills and get out. I don't want your pity."
"It's not pity. It's...we're concerned." Steve decided not to give in to Tony's sulking, and sat on the bed next to him. "Bruce told us about some of the things he's discovered, like foods that will make you sick, but what about what we don't we know?" Steve gave in to temptation and ran his hand over Tony's hair.
Tony closed his eyes, and that rumbling noise grew louder. "That feels ridiculously good. You have very warm hands."
Steve laughed and stopped petting him. "Take your medicine."
"Fine." Tony opened his mouth and let Steve drop the pills in, and then hold the glass for him to drink. As soon as he swallowed, he resumed humming.
"Why are you doing that?" Steve asked, putting two fingers lightly on Tony's throat to feel the vibration.
"Dunno. It just... feels better, makes it hurt less, or distracts me from it." Tony shrugged. "What's in the mug? Is it one of Bruce's weird teas? This one actually smells good."
"Yeah, it's something herbal. It's supposed to help you sleep." There was no way Steve was going to tell Tony that it was catnip tea.
"Give it here. Sleeping is better than being bored."
Steve helped him drink the tea, and then stroked his hair for a few minutes while Tony purred himself to sleep. Steve decided he'd better read up on cats. They'd never been his favorite animal. Too independent. Untrainable. Keep you up at night while they have loud sex in the alleys. He turned the light off when he left the room.
***
"I'm bored beyond belief," Tony said, while trying to fit a thin wire into his right cast to scratch. "Why can't I go to my workshop and have some fun?"
"Because two doctors said no, three if you count Bruce," Natasha said. She kept trying not to see cat behavior and mannerisms when she looked at Tony, but kept failing. It was unprofessional. She should not have the urge to forgive him for being annoying just because he looked up at her with wide and falsely innocent eyes. She should be cool and dispassionate. Well, maybe once he'd recovered. You're allowed to baby injured men, with no loss of dignity on either side."You've got cracked ribs and a concussion. You're the genius, you tell me how much fun movement induced nausea would be." She took the wire out of his hand and put a bed-tray bearing a bowl of soup in front of him. "You should appreciate the sacrifice I've made for you. Not only have I cooked Chicken Kalia, but I have perverted the recipe by omitting the onion."
Tony sniffed, and then poked at the soup with a spoon. "It has pickles in it?"
"Dill pickles. There is no garlic. Bruce oversaw the preparation."
Tony tried a spoonful. "This is... remarkably good. I didn't know you could cook."
Natasha smiled. "The last man who said that died at the table."
Tony didn't quite spit out the spoonful of soup.
Natasha grinned and tried not to find it cute.
***
Clint came and sat cross-legged on Tony's bed. "I had a cat once." Well, actually it had been a baby leopard cub and it wasn't so much his, as he was allowed to feed it because the mother wouldn't have anything to do with it. He still had a few scars from over-enthusiastic play, probably the only marks on his body that had been inflicted from affection.
Tony put his arm across his eyes. "Call me Fluffy and you die a horrible death."
"You're not really a Fluffy. I have a much better name for you than that." Clint waited until Tony got curious and put his arm down. "Boots! Yeah."
"A horrible, lingering death. It will become the star attraction at the waxworks tableaux. Strong women will mock you. Strong men will faint. Children, of course, will be fascinated. Kids like that sort of thing."
"Tiger?" Clint grinned. If Tony really didn't want company, he could claw as sharply as any leopard.
"Well, actually that's not bad."
"Really?"
"Of course, you'd have to be a beautiful woman to call me that."
"I'll get Natasha. I'm sure she'll be happy to call you Tony the Tiger."
"On second thought, no, not even beautiful women."
"I brought you a present." Clint nudged at Tony's shoulder.
"Does it explode?"
"No."
"I'm going to die of boredom." Tony sighed.
"Bruce said you could get up tomorrow."
"You'll find my shriveled body here, and be sorry, but it'll be too late then."
Clint handed Tony a laser pointer. Tony scowled at him. "So not funny. What's next, a ball of yarn?"
"Well you are knitting bones, aren't you?" Clint dodged Tony's half-hearted cast-swipe, got off the bed and went over to the far wall. He started taping up pictures of various villains, superheroes, mutated sealife, and Nick Fury.
Then he returned to the bed, and produced another laser pointer. He flicked it on and a blue dot got Fury in his eyepatch. "Feel up to pitting your cat-like reflexes against mine?"
"Oh, it's on." Tony's pointer was red, of course.
***
Thor strode into Tony's room and announced, "In Asgard there are healing rooms. Injuries as minor as yours could be cured within minutes."
"Mmm?" Tony looked up from SI's Interactive Swimsuit Issue. "Yeah? I'd like to see that. It's a pity your father won't allow Midgardians to visit."
"I have spoken to Frigga, and she has said she would intercede with the All-Father on your behalf!" Thor grinned at Tony's wide-eyed look of pleased surprise and gave in to the impulse to ruffle his hair.
Tony's eyes narrowed. "Wait a minute. We've all been banged up a lot worse than this. What makes me any different?"
"Why, my mother has, as you say here, a soft spot for felines. Her chariot is drawn by the most magnificent..."
"OUT!" Tony picked up one of the many pillows that had mysteriously migrated into his room and threw it at Thor. "OUT! I AM NOT A PET!"
"I shall return after you are in a better mood. Perhaps if you were to take a nap..."
"OUT!"
***
Bruce looked at the pile of pillows on the floor. "Is this a new game?"
"I'm making an obstacle course," Tony replied irritably. "All this is getting on my nerves." He waved his arms, indicating all the various small comforts and distractions surrounding him.
"Yeah, it's annoying having friends, isn't it?" Bruce picked up a couple of pillows and walked into the room.
"They all want to PET ME. Even when they don't actually do it, I can see it in their eyes. I am NOT a cat."
"Well, you are, a little." Bruce put the pillows on the bed, sat on it, and took a pen from his pocket. "Hold still." He pulled Tony's right arm across his leg and started writing on the cast, tiny precise lettering, as neat as the notes he makes in the lab.
"What are you writing?" Tony asked as Bruce kept going long after the usual 'get well soon' or 'ouch, this must hurt' quip. "The Declaration of Independence?"
"Close," Bruce said cheerfully, continuing to angle the arm so Tony couldn't see it. "There." He capped the pen and got up. "It's funny. You always wanted to pet my inner animal, didn't you?"
"Well... not pet... exactly. You're just..."
"Different? Interesting? Unique?" Bruce smiled and reached out to stroke Tony's hair despite his glare. "Really, Tony, when you get right down to it, we all are. It doesn't make us less human. It makes us more."
After Bruce left, Tony looked down at his arm to read the inscription. 'Of all God's creatures, there is only one that cannot be made slave of the lash. That one is the cat. If man could be crossed with the cat it would improve the man, but it would deteriorate the cat.' - Mark Twain.