Sentinel/Guide AU for starkingenuity

[starspangledspandex]

Things have been going remarkably well between them. Even if the beginning was somewhat rocky, their compatibility was obvious and not just to them. Steve was old-fashioned and though his instincts made it clear what they wanted, he did things the "right" way. There were dates and gifts and just general wooing. They talked about it and they were ready.

He smiled at Tony, watching him as he worked and couldn't stand it anymore. "Tonight," he said, then added, for clarity, "We should bond tonight."

Maybe not the most romantic proposal but he figured he shouldn't smother Tony in it anyway or the man would get sick of it. No the rarity made it special.

Comments

[starspangledspandex]

It was asking for all kinds of trouble. He was already older than most Sentinels without a bond. He knew that was the point of the serum but it was still going to be a problem at some point. His eyes turned to Tony and said, "Even Erskine didn't think the serum would permanently remove a need for a Guide. It was meant to make super soldiers more resilient in the field, not independent. The army wanted independent but Erskine wouldn't do it. He said to take away the capability to bond not only took away something beautiful but it removed something that a Sentinel needed for the sake of their morals."

"SHIELD is looking for any of Erskine's notes that they can find," Bruce said quietly. "Because Steve's right. The super soldier program never meant to replace Guides. They just wanted to keep Sentinels from needing them in the field. We lost a lot of Guides because their Sentinels needed them close. But, even Erskine wasn't sure of all the side effects."

Lucky for them, his work with the Hulk and the military gave him plenty of insight into Erskine's intentions. He wasn't sure if it would help but it might.

[starkingenuity]

"So... We tweak it? Beta blockers? IAO inhibitors? Lots of alcohol?" Tony sounded like he was cracking just a little. His voice seemed almost weak and his humor was more like desperation.

He swallowed when he saw how grim Banner looked. He wished he didn't have to glance at Steve to know what he was feeling now, but he did.

"Just tell me what I can do."

Tony's bonding heat might have been controlled by drugs, but the emotions welling up because of it weren't something easily discarded.

[starspangledspandex]

"I don't know yet," Bruce told them. He wasn't a miracle worker. He spent years studying the serum but that didn't mean he knew everything about it. Obviously, otherwise the Hulk wouldn't exist.

Steve shifted to wrap an arm around Tony. He didn't know what else to do. He could hear the pain and heartbreak in his voice and there was nothing he could immediately do to help him. Sentinels weren't supposed to hurt their Guides like this! Steve felt guilty and heartbroken. This was supposed to be such a wonderful thing.

Why couldn't one thing in his life go right?

"We need to do some tests. Maybe one or two on you but..."

"I'm the problem," Steve finished, because there was no doubt in his mind and Bruce nodding in agreement only made him feel worse about it.

"Some of the tests... are uncomfortable," Bruce told him. "But we have to know what's going wrong before we can try to fix it."

[starkingenuity]

Uncomfortable wasn't a word anyone liked to hear but what choice was there? With Steve's arms around him, Tony just felt an ache. His biology told him to bond. To do it now. Quickly. There was a compatible Sentinel right there--

He'd never wanted or ached for something so badly in his life.

Steve was not going to be able to do the tests with Guides around, however, and so Tony was talked back to bed to rest off the drugs while Steve was led away. Fury was waiting with a pair of young scientists who kept finishing each other's sentences. Both were normal, neither Guide nor Sentinel. Both almost squealed to see Captain America.

"Leo Fitz."

"Jemma Simmons."

"Great to meet you."

"So great. Brilliant even!"

"Yes, brilliant!"

[starspangledspandex]

His biology probably wasn't making it much better. It was one of the reasons he didn't understand what was happening. He didn't want to leave Tony. He wanted to have him and claim him so even if he walked away other Sentinels would know he was Steve's.

He glanced back over his shoulder even as he left, blue eyes torn, but he walked away because he needed to do they could figure this out.

Steve was not as thrilled as Fitz and Simmons, but there was a lot on his mind right now. He really didn't want to put up with it but he trusted that these were some of the best and brightest from SHIELD. If this what it took, well, he had been through worse.

His smile was tight and he nodded curtly, offering his hand to each of them. "Pleasure."

[starkingenuity]

Both scientists seemed to giggle a little after they shook Steve's hand, though Jemma got immediately to work on biometrics and Leo went to help Bruce with the machine they were tinkering with. That left Steve alone with the mousy Brit, talking away her nervousness.

"Your nest really looked lovely," she was saying as she drew blood from him. "Everyone was talking about it. I think Fitz was a little disappointed that there wasn't anything hi-tech on here but I did try to remind him that just because Mister Stark is his idol, and just because he is a brilliant engineer, not everything has to contain wires and servos!"

[starspangledspandex]

His forehead creased at the compliment and it wasn't because he didn't agree, it was more because he was unaware anyone else had seen it. Tony might not have mentioned it to him. He was quiet for a moment before he asked, "How did you see it?"

[starkingenuity]

Oooh. Jemma flushed and flustered as she prepared some slides. "Um-- do you use social media? Where there is a photo sharing website. Mister Stark posted a photo and-- it certainly went viral! A lot of Sentinels were very disappointed to have lost out to you. He rejected so many, it's fairly well known how unsusceptible he's always been to their advances. In fact, before you, he'd only ever dated non-Sentinels! Well. Dated might not be the word."

She talked when she was nervous and now she was very nervous.

"I think it's romantic. Waiting all this time for you-- I've always envied that a bit. Being linked to someone-- We'll figure this out, Captain. You have my word."

[starspangledspandex]

"I don't, but I know what it is," Steve replied and of course Tony posted it all over the internet. Steve was relatively used to the Guide doing that sort of thing. Now, though, the whole world was going to be assuming they bonded when in fact he was defective in some way.

It really didn't help hearing about all the people that Tony turned down either though he appreciated her attempt to make him feel better.

"Thank you," he said quietly. "I hate that it was ruined this way."

[starkingenuity]

"Not your fault, Captain. My theory, well, Doctor Banner's really, is that there is a dislodged protein in your adrenal glands. It was actually a fairly common problem with Sentinels of your time period. Lacking proper nutrition, being ill-- there are papers that claim that you were actually born a Sentinel but had been missing part of the gene that allowed for growth and strength. It's all very fascinating."

Jemma would just keep on jabbering away as her equipment did the initial scans and she flashed the results up on the screen. "Oh! Look! Interesting, I'm surprised no one did these basic flatline tests on you. See here, your cells? You weren't born a Sentinel, Captain... You were born a Guide."

[starspangledspandex]

He tried to follow her rambling as much as he could. He stared at the cells, the pictures were meaningless, but her words were not. He might have been a Guide. He wasn't sure if there even was testing like that when he was enlisted.

"But I'm a Sentinel now," he clarified, because that much was very obvious and was apparent just from his experiences in this century. His instincts were all Sentinel as well. "I don't have any Guide instincts, just Sentinel ones."

[starkingenuity]

"Mmmm... Yes. Yes that's very true. You do. The serum overwrote-- Here. That is a very big Sentinel gene. It's also a Guide gene but certain proteins gets turned off or turned on depending on which a person is meant to be. Erskein was able to turn this sequence off and overwrite it. It's what made you capable of doing without a Guide for so long. It's still in your base code here-- this is what regulates bonding heat."

Jemma frowned. She pulled the monitor back towards her.

"So what happened then? Did you not go into heat-- Sorry that's so rude! Pardon me. But I'm curious. This doesn't make too much sense. There are genes here that were never overwritten by the serum and we don't have the serum to test to see why either. But this is why it did to doctor Banner what it did. He was born quote-unquote normal. It converted his genes to Sentinel genes as it converted yours... Basically it's like he goes into bonding heat whenever he become the other guy. You have the opposite issue. Maybe. It's all just a theory captain. We will know more soon."

[starspangledspandex]

There was more rambling he didn't understand as she adjusted the slide and pointed out another blob. He would have to take her word for it. "So the serum didn't work as intended," Steve summarized slowly, trying to make sure he was understanding what Simmons was saying. "It only worked because I was already a Guide."

He inhaled slowly and said, "No, I didn't go into heat. I feel the compatibility with Tony. I have all the right instincts. It just didn't... happen."

[starkingenuity]

"I have no doubt that you are compatible. I've seen the scores. Well done really. My thought at the moment is that you didn't go into heat because you can't. It could be as simple as Gene therapy... Or..."

She didn't say it, but it must be obvious to Steve now. He might not be able to bond at all actually. That underlying part of him that was still a Guide might never let him complete the bond.

"We will do all we can," she promised.

[starspangledspandex]

The way she trailed off made it very obvious just how dire their situation was right now. He might never be able to bond. What did that mean for their relationship? There was no one more compatible but surely Tony wouldn't chose him and never bonding over that feeling of completion?

Besides, it was likely Steve would go crazy at some point anyway. Without a bond, he was going to be useless at some point. Maybe the serum and the Guide cells in his blood would prolong it but it wasn't going to stop him from needing that bond.

"I'll do whatever it takes," he repeated to her.

[starkingenuity]

Right now there was nothing for Steve to do except take Tony home. He was no longer making bonding calls and his body temperature was back to normal. His hormones had equaled out and Banner warned them not to get too frisky... Though certainly not in those words.

It would be up to Steve to fill Tony in on what was happening and the tests he would have to undergo once they finished their preliminary analysis.

Right now, though, Tony didn't care. He was tired. He missed all of his stuff. And he had a nest to deconstruct. It didn't feel right just leaving it there.

[starspangledspandex]

They only briefly explained one of the tests which Steve assumed was one of their own design. The rest were given to him in a list so that he could look up the specifics. Once they were ready for him, if the blood tests didn't show anything, they would call him back.

So Steve took Tony home and he was quiet on the trip, knowing there wasn't a good way to explain any of this. At home, he explained it all, everything that Simmons told him. He repeated the same words as her because Tony would understand it more than him.

"So they don't know what's causing it," Steve finished. "It might not even be related to the serum but it looks likely."

He was trying to be strong but it was hard to do, especially seeing the nest again. Steve just wanted to hold onto Tony and never let go.

[starkingenuity]

"You were a Guide." Well, Tony had never been into Guide on Guide porno (the world was weird and the porn just matched it). Sentinel on Sentinel-- Okay maybe. What? He had his tastes too! Still, Steve didn't give off Guide vibes at all so Tony just looked skeptically up at him and then took the blond's larger hand and pulled him out of his bedroom. He had other bedrooms, almost as good.

He didn't want to look at the nest, not out of sadness or loss but because he could feel himself reacting to it. He wanted to bond in the worst way. Tony counted to three silently in his head and gave the Sentinel a shove onto the bed. It might not budge him, but he hoped Steve played along so he could climb on top of him.

It wasn't a very Guide like thing to do, but Tony wanted to be kissed so he decided to take it for himself.

"That explains why you cried during Bambi."

[starspangledspandex]

"Were," he echoed, because it was no longer true. He was basically all Sentinel now except, it seemed, for some pesky genes that might be getting in the way. It was frustrating and annoying and above all sad for him. He felt the loss. He was a Sentinel and he had plenty of old-fashioned ideas of what that was supposed to mean.

He let Tony pull him out of their room and into a different one. The shove to the bed was unexpected but he did go along with it. He wanted the Guide to be happy. He was already failing at that today.

Steve pressed up into the kiss. Firm and steady and unmistakably Sentinel. He wanted to flip them over and finish what they started yesterday.

"You're not human if you don't cry at Bambi," Steve replied with a small smile.

[starkingenuity]

"Boop beep boop," Tony replied to the human comment, grinning as he leaned over Steve to kiss him. It was sweet, he was trying to be good, even if his hands smoothed over the large chest beneath him.

Nothing had really changed between them and it would be all right. Tony was trying to prove that as he looked down into blue eyes that so affectionately and fearfully looked up at him.

"If we can't bond, then we can't. But you're still my Sentinel. And I fully expect to get into your pants either way."

[starspangledspandex]

He chuckled lightly, appreciating his Guide lightening the mood a little and enjoying the feel of the man's hands on him. He was afraid of what was going to happen. Tony wasn't wrong. Steve already lost so many people to time. It would hurt so much to lose another one to this.

"You are more than welcome in my pants," Steve said, eyes amused as he added, "I'm not sure we'll both fit in here but we'll figure it out."

He cupped Tony's cheeks and pulled him gently down into another kiss, eyes serious. "I'm going to try everything to fix it. If we can't... you know the long term side effects. It might take longer for me to get to that point but it's still going to happen."

[starkingenuity]

Steve had to bring up the mental instability and eventual descent into a fugue that could never be broken. Tony stilled, large eyes narrowing. "Eventually means that we have a lot of time still to figure this out. We know I can pull you out of trances. You zoned during the Chitauri attack and I brought you out of it. So you're not a complete lost cause."

He stroked the blond stubble on the beautiful face of the man below him.

"I promise you that we're going to fix it. I intend for you to still be around when I transfer my brain into a young new body."

[starspangledspandex]

Jealousy. Paranoia. Protectiveness. Sentinels without Guides often got violent, especially if they were fixated on a Guide or dating one. The higher the compatibility the worse it tended to be. Then, there would be the memory loss. The patches of time lost to brief fugues. It would get worse and worse, until yes, he fell into a fugue nothing would pull him out of.

They called them the Walking Dead when he was a kid. Blank stares, shambling, filthy people that starved on the streets. It was apt, he supposed, that zombies shared a similar description. Even fugued Sentinels could be violent. He wondered if that was where the idea of the creatures originated.

He smiled, thankfully, for having a Guide so wonderful. He believed it when Tony said that and he meant it when he said it in turn.

Steve tilted his hand into the hand and teased, "You might need a younger body to keep up."

[starkingenuity]

"Says the virgin!" Tony gasped, pushing Steve away without much force and not expecting him to go anywhere. He was not going to consider their very brief connection in anyway being the breaker of Steve Rogers' virginity, thank you. That was still to come when the blond could accept a forming bond and they could become one person for a little while.

"I have so much experience that I could split off into multiple versions of myself and-- Actually no. One of me is just fine. Could you imagine two? You'd be a lucky man until I killed myself over design schematics or how much sugar goes into a latte."

At least they were joking. At least they weren't talking about the Sentinels locked away be use they had not been compatible with or accepted by a Guide.

It happened. It was rough but it happened.

[starspangledspandex]

"I have a lot of time to make up," he grinned and it wasn't quite as cheerful as normal. All those other thoughts were still at the back of his mind. He was, after all, the one that was going to go insane if they didn't fix this.

Steve didn't really want to consider that his first time either. He raised an eyebrow at his Guide's rambling. "I think that would be a little strange," he told him. "I like only having one of you."