This didn't quite turn out how I wanted but the main scenes I had imagined are there so eh. I like fics where the Guardians are confused by Terran biology and I ship Starmora a little and something about Ego's entire plot bugged me so I rolled it all into one for this story.

This job had involved a lot of running. A lot. And when they finally stopped running it was because the Guardians found themselves in the lowest part of a washed out basin of rock, trapped with the thing they had been hired to get away from the village.

"Peter, run!" Gamora commanded, slicing wide to clear some room before ducking and running after him. She had thought Rocket's distraction would go off quicker, but when it failed she and Peter found themselves wedging further and further into a crack in the rock, trying to shelter from the darts the creature was shooting at them.

"Peter, move!" Gamora commanded, shoving her shoulder aggressively into his chest until he fell backwards and she literally pushed him into a new pocket.

"Ow, Gamora, I did not need help."

"Really?" she challenged, pulling herself sideways out of the crevice and struggling before she finally got her boot free and turned around, hands on hips. "Because you seemed pretty stuck."

Peter got up, brushing off his coat and tugging it once to aggressively straighten it. "Well I wasn't."

She rolled her eyes, peering through to see how the battle was progressing.

"I'm going back out there, this is ridiculous and Rocket will never let me hear the end of it," Peter said, clicking his phaser open and marching straight for the way out. Gamora whirled around and pressed her hand against his chest, her brow furrowed for a split second and her lips drawn back to yell at him before she froze, her eyes going wide. She looked down at Peter's chest and he immediately stopped fighting her.

"What?"

She blinked and pulled her hand away like something had startled her. "Peter," she said slowly, eyes still focused on his chest.

Peter was starting to feel incredibly uneasy. "What, Gamora? What are you staring at my eyes are up here." He snapped his fingers and she missed his nervous smile because she couldn't seem to look away. Slowly, she reached out and placed her hand against his breastbone again, and he didn't think someone with her complexion could pale but she did.

"Peter...do you feel alright?" she asked, looking at his eyes for the first time.

"Well I did but now you're looking at me like I'm dying so there's some queasiness going on."

"Don't worry, I can fix this," she said, drawing her hip dagger.

Peter really didn't like her expression then and he backed up, shaking his head. "Gamora..."

"You have something inside you Peter, I'll get it out and you'll be okay."

He blinked, staring at her as his back hit the rock with a thud. "Something inside me-" he slapped his palm against his chest, feeling around and lost in utter panic for a split second before it was replaced by utter confusion.

"Gamora there's nothing inside me what are you on about? We have to get back out there! Rocket is gonna finish without us and you know how he is with claiming extra shares."

"Peter, how do you not feel that? You have some kind of-" she gestured with her knife "parasitic entity inside your chest."

He made a face, shaking his head once. "What are you talking about?"

"Here-" she jabbed his chest, pulling back again like the thing might jump out and bite her. "Right there. Can't you feel that?"

He stared at her for a long couple seconds. "You're kidding me right?"

She huffed and tossed her hair the way she did when he was exasperating her. "Does it look like I'm kidding? Clearly the parasite has some kind of numbing agent keeping you from feeling pain, so I'll just make this quick-" she raised the knife again and Peter was genuinely terrified for his life.

"WOAH WOAH GAMORA STOP!" he shouted, raising both hands and hunching his shoulders as he pressed into the rock. "That's my HEART, what you felt is my HEART. You can't cut that out I need it to live!"

For a horrible moment Peter was afraid she didn't believe him. She narrowed her eyes at him before lowering the knife a few inches. "Are you certain?"

"Am I cert-" the knife came back up. "YES. Yes, one-thousand percent yes put the knife away!"

She sheathed it quickly, shaking her head, glancing back out of the crack. "It seems the fight has ended."

Peter pushed off the rock. "Woah no, we are not just going to end the conversation like that, not when you were about to dig my heart out of my chest over a misunderstanding." He looked down her body and back up. "Did you really think my heart was a parasite? Does your species not have a heart?"

Gamora rolled her eyes, turning back around. "My species has three, and they are much..." she glanced down at his chest as though judging his organs. "Quieter."

"I have a lot of adrenaline in my blood right now thanks in part to you, sorry that my heart is too-" he gestured vaguely. "Loud for you. Or whatever." He frowned.

She waved a hand. "You cannot help your biology. It was just so—violent. I had not imagined it could be a natural part of you." She turned sideways, working her way back into the crevice to re-join the others.

He blinked at her. "Violent. My heart beating is violent but you drawing a knife to carve it from my chest isn't!?"

She huffed and gave him a look, working into the tunnel. "I thought you were in danger, would you rather I choose to let you die by being eaten alive from the inside out?"

He grimaced and looked away, rubbing his hand over his chest. "No," he said petulantly.

"Then you're welcome."

Peter had thought that was the end of it, but it turned out Terran biology was singularly unique among most species in having a solitary heart located mid chest that could usually be found by touch or sound.

Groot, it turned out, did not have a heart at all. He had sap that moved around by some law of physics that Peter didn't begin to understand and the closest organ Drax had to a heart was actually more of a set of churning structures lining the bottom of his ribcage.

"Does nobody on this team actually have a heart besides me and Rocket!" Peter said loudly, the mental image of his team accidentally killing him over a misunderstanding on something he thought more universal on loop in his brain.

Rocket raised a hand from his spot lounging with assorted bomb parts in his lap. "I actually object to that assumption, I am heartless."

"I am Groot."

Rocket flicked his ears and rolled his eyes. "Course I'm not literally heartless, thanks captain obvious."

Drax's brow was furrowed as it had been for the past five minutes since the revelation about Peter's anatomy. Peter stood there with his hands on his hips and his lips pressed together for a long beat before he decided to open the can.

"Okay Drax, what's confusing you this time?"

"If your heart is vital for life, and you only have one, how is it Gamora could break it and you are not dead?"

Gamora's eyebrows went up and she folded her arms very slowly, pivoting to look at Quill, who was re-thinking ever telling Drax anything.

"Dude, I was drunk and it's a figure of speech. Remember how we talked about those? I said she broke my heart because what she did hurt me and I felt it in here," he pat his chest. "My heart."

Drax looked even more confused. "Your brain does not feel emotions? It is your heart?"

He shook his head, rubbing at his forehead. "Look, forget it. Just-" he put both hands up, trying to re-set the room for a moment. "Bottom line. I am half Terran. You all knew this." He looked around the room, eyebrows raised. "I have a Terran heart. One heart, right here," he pointed at his chest. "I need it. I am very attached to it. Don't touch it. Thank you."

He dropped his hands and left before Drax could ask something else.

For a long time the subject was dropped, until one night after a close call for Peter, Gamora couldn't sleep. She sat at the front of the ship, hugging herself and watching the stars for a long time before rubbing at her eyes and wishing she could just stop thinking. Not even the peace of a quiet cockpit was helping, and she bit at her nail for a while, debating as she kept glancing towards Peter's room.

She shouldn't bother him. But it couldn't hurt to check on him...right?

She fought with herself for a moment more before getting up and moving through the ship, headed for Quill's room. She paused when she crossed through the lower deck, realizing that he had fallen asleep in front of the back window, back resting against the ship's warm wall where he'd made a nest of pillows. She smiled softly, watching him breathe peaceful and deep for a few moments, the starlight cast across his body.

Starlord indeed, she thought fondly. He was fine, just exhausted, and she was being stupid.

She leaned her hip against the table and watched him for a few moments, a spark of curiosity touching the back of her mind now that she was feeling calmer. Quietly, she walked the rest of the way to Peter's sleeping form and knelt next to him, studying his face for a few seconds before very carefully, very slowly reaching out her hand and resting it on his chest. She concentrated for a moment, but she couldn't feel more than the warmth of his body and the gentle flex of muscle and bone as he breathed.

Maybe Terran hearts stopped while they slept. That would certainly explain how it could beat so violently the rest of the time. The idea of a heart that worked only some of the time was a foreign concept to her, but so was the output of power his heart had shown. If Terran hearts really worked that hard it was little wonder they had such short lifespans.

But Peter didn't...did he? He was half immortal. That could mean anything...

She looked at his face again, her brow furrowing. That soft movement by the base of his throat...she reached out to brush her fingers along it, feeling the throb of blood warm under his skin. So his heart beat even while he slept. She supposed she shouldn't be surprised. He was always moving in some capacity, like his life force was brimming over and had to be spent with a twitching leg or those ridiculous dance moves he so enjoyed.

Peter had said a Terran heart could be listened to without the use of instruments, and Gamora wanted badly to know what it sounded like in that moment. Gingerly, she withdrew her hand and watched his face until the last second where she turned her head and rested it against his chest. At first she was tense, afraid of waking him, but then his warmth started seeping into her cheek and his body felt nice against hers so she relented, relaxed. The sound...was incredible. She'd never heard anything like it. Much slower than the forceful rhythm she'd felt during that battle, but somehow still so strong. It was a deep, resonant sound, filled with warmth and a drowsy vitality.

She heard him humm and his fingers were suddenly in her hair and she tensed, almost picking her head up and then fisting her hand in his shirt instead.

"'Mora..." he murmured, gently stroking down her head and over her back. "Whass going on?"

"Apologies," she said softly, head still pillowed against his strange, half Terran heart. "I did not mean to wake you."

"What were you doin then?" he asked, his voice thick with sleep. He didn't sound angry, just curious.

She hesitated for a moment and felt him raise his head a little, probably to try and see her face. His fingers tapped gently against her shoulder.

"G'mora?" he really shifted then, but she didn't want to stop using him as a pillow so she just tightened her hold on his shirt and shook her head a little.

"I was curious, that's all. I wanted to know if your heart continued while you slept. It is strange to me, that you have a heart that is so full of life during a battle and yet it doesn't drain the life right out of you."

She realized then that the uncertainty about Peter's lifespan bothered her. Far more than she'd ever been willing to admit before. The image of a lifeless Peter—of all that vibrancy and enthusiasm and energy just gone from his body—it made her cold all over.

She felt Peter listening, but his breathing had picked up which meant he was coming more awake. She hadn't intended this at all.

She lifted her head and gave him a pinched smile. "Forget it, I'm sorry I woke you, get some sleep."

She moved to get up but he caught her hand against his chest and rest his free hand against her waist, keeping her there.

"No, stay. It's okay." He sought her face for a moment, and he was so quiet and serious that it made her uncomfortable under the gentle searching. She was used to flippant, sarcastic Peter. This Peter always gave her pause and made her feel vulnerable and warm all at the same time. She was still getting used to that feeling.

His thumb rubbed against her hand and he smiled softly. "Gamora, I promise you what you felt, what you were listening to just now is what my heart is supposed to sound like. Even got checked out the last planet we were on after the whole Ego incident. Terran hearts are one of the strongest organs in the body, and being half immortal only took the edge off. Feeling it pound during battle, that's completely normal. It's healthy."

She frowned lightly. "I thought Ego—when we killed him..."

He shook his head. "I've been thinking about that actually, knew something in his logic didn't sound right. He called me a battery Gamora. What good is a battery if it's drawing its power from something he already had access to? Only logical explanation is while maybe I was harnessing Ego's power to create those things, I have some light of my own hidden somewhere inside. I just haven't tapped into it yet. But I do have a hunch where it is."

"Your heart."

He shrugged one shoulder. "That is how I accessed my powers the quickest, and it was the first place Ego...targeted..." he grimaced a little at the memory. He still felt sick, remembering that burning, leeching presence winding itself through his veins and overtaking his nervous system like a virus.

Gamora's soft touch against his cheek brought him back and her look of concern grounded him again.

He sighed, resting his head back against the nest of pillows and offering her a small smile. "I'll be alright."

She looked at him for a while, as though making sure he wasn't lying. When she finally seemed satisfied Peter half expected her to leave but she didn't move. Instead, she lay her head on his chest again, closing her eyes as a small smile touched her lips.

Peter smiled back, ran his fingers through her hair one more time, and rest again, letting her comforting weight draw him back to sleep even as his heartbeat drew her into her own rest.