A/N: *slams fic down* I STILL HAVE LIKE AN HOUR LEFT OF FATHER'S DAY I'M NOT LATE

Anyways. I came up with this AU a little while ago, fell in love with it, but hadn't posted a thing until I realized hey, Father's Day is coming, I should post a thing for that. So here it is! One of... many ideas I had, and the only one I figured out how to finish. Writing is. So fun. I hope you enjoy!

Tiny background note: Everyone is like four years younger here than they are in canon (except Chekov, who I just dropped to 16, bc a 13yo navigator is... a stretch, but he doesn't come up in this) and at least the core four were all friends at the Academy

Leonard followed Jim into the transporter room, pausing when he stopped to comm Sulu back on the bridge. Stepping aside to let Spock and Nyota by, he took a breath, and for the first time since he watched Jim take the captain's chair and order them on a pursuit course, he found a moment to process everything that had happened.

He had known, from the time Jim convinced him to enter the Academy to recover from the divorce, that one day, Jim would outrank him. Leonard's dreams began and ended in medbay, healing the wounded, and if the rank on his wrists never surpassed lieutenant commander, that was just fine with him.

But the kid dreamed of the stars, of watching them race by from that one particular seat on the bridge. He dreamed of being at the center of the action, of being the head and heart and soul of a thousand people depending on him to make the right decision, and Leonard supported it wholeheartedly. How could he not, when he had seen the first stirrings of the dream awaken a spark of life within him, an excitement for the future that the homeless, lonely, hungry, defensive fifteen-year-old Leonard had met in jail could never have hoped to feel?

He had just expected that day to be a long way off, and under far less dire circumstances.

Now, instead of watching a mature man in a well-deserved gold uniform order them out of spacedock for a simple trip to a new planet, he was watching a bruised, somewhat bloodied, all around battered twenty-one-year-old charge off into the heart of a twenty-fourth century Romulan ship in just the black undershirt that meant he wasn't supposed to be there.

Jim finished his talk with Sulu and made his way to the transporter pad. Leonard stepped up beside him, ignoring Spock and Nyota kissing right beside them, because as much as they had tried to hide their growing crushes on each other, they all knew about it, and it was utterly unsurprising that they were finally deciding to act on it. In fact, in nearly any other situation, Leonard would probably be tossing an "It's about damn time!" at them.

But here, in this situation, with the fate of the world and the Federation hinging on the next move of a few cadets, Jim alone had his attention. "Are you sure about this?"

"Of course I am," Jim said loftily.

"Jim."

He looked at Leonard, and while he had learned years ago to read between the cracks in the cocky persona Jim used as a shield, he couldn't deny that there was a genuine confidence in his eyes now. "It's what I have to do, at least," he said, softening with a small smile. "I've got this, Bones."

Kids grew up. Starfleet officers got promoted. These were two basic facts of life, ones that Leonard had always known.

Accepting it and forcing himself to take a step back, clearing the pad for Jim to beam off into the dangerous unknown, when all he wanted to do was drag Jim to medbay and erase the injuries marring his young face, was still one of the hardest things he had ever had to do. "Good luck, kid," he murmured.

The words were all he had to offer.

Beside him, Nyota backed away from Spock, her own parting words hanging in the air between them, and Jim's order to energize almost made Leonard flinch.

That's my kid. Barely old enough to drink. Running off to fight a guy who can destroy planets.

As the flash of the transporter beams died away, Nyota rested her hand on his arm, and the silent message was clear:

I guess we'll just have to get used to this.

-LLAP-

Of course.

Of course their first ever normal mission would result in them being arrested.

Leonard paced the cell, arms crossed, the pounding in his head from the blow that had knocked him out only irritating him further. That, and the extremely itchy, ugly brown clothes they had procured in a failed attempt to blend in. Jim fidgeted with the bars, giving them experimental twists and tugs. From his spot sitting serenely on the rickety bench, Spock advised, "That is illogical."

Jim gave one bar a particularly firm shove, frowning at whatever results he didn't get. "Trying to escape doesn't seem all that illogical to me."

"This civilization is extremely adept at construction," Spock reminded him. "It is highly unlikely prison cells would be the one area in which their execution is lackluster."

Leonard shot him a glare at the use of the word execution.

"Everyone thinks that," Jim said, trying to stick his head through the bars, "but people escape all the time."

Leonard took a fistful of his shirt and yanked him back before he could get his head stuck. "You've never been one of those escapees, Jim."

"No," he agreed, shaking Leonard off and shooting him a pouty look as he smoothed his ruffled shirt. "But I've gotten out."

"Because I was on the other side of the forcefield convincing them to release you," Leonard retorted drily. "You had nothing to do with it."

Jim tilted his head so the light caught his round puppy eyes, sticking out his bottom lip. "I like to think I had something to do with it."

"Oh, please," Leonard muttered. "You were acting pissed, not cute."

"Then why'd you take me home?"

"Because I didn't know what I was getting myself into."

Jim put a hand over his heart. "I am frankly offended that you would imply I have ever caused you a single problem."

"I ain't implying anything, you have caused-"

"Gentlemen."

They looked up as Spock rose to his feet in a single fluid motion, keen eyes trained on the approaching guards Leonard and Jim had missed through their bickering. Immediately, Jim hardened into the confident captain's stance Leonard had often seen him practicing in the mirror, stepping up front and center, putting Leonard and Spock behind him. "Why have we been arrested?"

This particular species had pale grey skin, their wrinkles resembling cracks in stone, and the guards wore long cloaks with hoods that cast their faces in shadow. The lead guard, one of three, stout in stature but commanding in air, pointed at Spock, who had been the first to be singled out by the police out on the street. "You. Come."

Jim lifted his chin, shifting in front of his first officer, and Leonard saw his hands flex like he wanted to clench his fists, but he forced them to stay open. "I am the captain. If you have a problem with my people, you take it up with me."

The guard blinked eerie yellow eyes, but otherwise did not react. "You, then. Come."

The second guard inserted a key into the lock, twisting it with an ominous clank.

Leonard couldn't help it – he grabbed Jim's arm. "Kid-"

"Doctor," Jim rebuked, flashing a sharp look at him.

Right. Captain. Decorum. That stuff.

He forced himself to let go, to drop his hand, as the door swung open with the harsh squeal of unoiled hinges – unoiled, Leonard suspected, specifically to give prisoners the heebie-jeebies. The third guard grabbed Jim's arm with a visibly vicelike grip, pulling a gun from beneath his cloak and training it on the captain. Jim stiffened, and with his free hand down low, he gave them a subtle gesture: Don't fight.

Leonard glanced at Spock, and though his lips pursed into a thin line, he obeyed, and reluctantly, Leonard followed his lead.

Why did I ever agree to this?

The door slammed shut in their faces, and their retreating footsteps echoed back to them long after they disappeared from view.

-LLAP-

"It's him, Bones, I know it is."

This time, it wasn't command structure holding Leonard back. Not exactly, anyway. No, this time it was just the stupid, stupid need to hold Jim back because he was the captain of Starfleet's flagship and he couldn't be rash, even when he had every reason to completely lose it.

"Calm down, Jim-"

"Calm down?"

Jim stopped his frantic pacing of his quarters to stare at him. "Bones, how the hell am I supposed to calm down when the man who slaughtered four thousand innocent colonists right in front of me is on my fucking ship?"

The panic in his eyes, in his fidgeting hands, in his disheveled hair stabbed Leonard in the heart. "Bad choice of words," he amended, keeping his voice low, struggling to keep Jim from flying any further off the handle. "I'm not saying be calm, I'm saying- just act calm. Ok? The face doesn't match, the voice isn't a perfect match, so it might not be him."

Jim stumbled back a step. "You don't believe me."

"No!"

Leonard paused, wrangling his voice back to some semblance of even and steady. "I believe you, kid," he reassured him. "I know that there isn't a chance in hell you could ever forget Kodos's voice. But he's had surgery, damn good surgery, his voice has changed, and he's even had his damn DNA altered. Your word may be good enough for me, but that alone won't convince Starfleet that this apparently peaceful actor is a genocidal terrorist everyone thinks is dead."

"It's him," Jim insisted, voice cracking, tears threatening to cascade down his cheeks. "It's him."

"I know," Leonard said, reaching out to draw him into a hug. "I'll help you prove it, but we need help. If you would just tell Spock-"

Jim flinched violently away, shrinking from Leonard's attempt at physical affection. "No."

Leonard's voice was a plea. "Jim-"

"I'm not-" He stopped, scrubbing a vicious hand over the escaped tears. "Everyone who knows is in danger. It's bad enough that you know – I'm not dragging anyone else into this. Not Spock, not Nyota, not- not anyone I care about."

"You can't do this alone," Leonard protested.

Jim set his jaw, and the sudden shift in his stance was heartbreakingly perfect. Were it not for the reddened eyes and a few tiny spots of shimmering wetness that he hadn't managed to wipe off, it would be impossible to tell that he had been little more than a haunted, terrified kid half a second earlier. "No. This is my fight. Stay here, and don't talk to anyone. That's an order."

He turned on his heel and marched out of the room.

"Jim!"

-LLAP-

Pain rolled through Leonard at every breath. He pressed a hand to the blaster wound in his stomach, his entire body aching from the force with which he hit the rocky ground. Jim had dragged him into the meager shelter of some boulders, and he and Spock were putting up a valiant effort, but considering the three sides not flanked by advancing enemies ended in a cliff with a very, very long drop to the forest very, very far below, Leonard wasn't all too thrilled by their chances.

One of their defensive boulders exploded in a burst of blasterfire, sending shards of rock flying. Spock threw himself aside, and Jim dove to shield Leonard, Leonard throwing up an arm to cover Jim's head.

In the precious seconds Jim and Spock wasted not shooting, their attackers let loose a vicious barrage of unimpeded fire.

They scrambled to recover, shooting wildly into the crowd, but even if two stood a chance against two dozen, the ancient rock was giving way to the destructive weapons. A chasm of scorched rock opened up between them, trapping Spock in his own corner of their prison, and Leonard barely had time to look at him in horror before he heard a yelp from his other side.

He twisted around to see Jim sliding towards oblivion, the ground beneath his leg crumbling beneath him.

Acting on pure instinct, he lunged onto his elbow, grabbing a fistful of Jim's arm. Jim dropped his phaser, clawing for purchase, but loose gravel simply rolled beneath his fingers, broken shards slicing his skin. Leonard thought he heard Spock stop firing, only to resume immediately, unable to even attempt to reach them.

Gritting his teeth, Leonard braced his hand and feet against the rock, searching for what little leverage he could find, and pulled.

Gradually, millimeter by millimeter, Jim edged closer to safety.

Well. Relative safety, at least. Death was slightly less certain on their ledge.

Then his eyes flew wide. "Bones, down!"

Now used to taking orders from his kid, Leonard obeyed on instinct, flatting himself to the ground.

The blasterfire skimmed over his head.

Gravity yanked Jim viciously downwards.

Still clutching his arm, Leonard pitched forward after him.

He caught himself at the last second, hooking his arm around one rock and catching his ankle on another. Jim clung to his arm, his blood streaking down Leonard's sleeve, his entire body now dangling helplessly in thin air, every foothold he tried to find crumbling to dust.

"Hold on, kid," he gasped. "I've got you."

Well, one small blessing of their current situation: Their attackers seemed to have discarded them as a threat worth pursuing. No one was shooting at them anymore.

That didn't change the fact that Leonard's grip on the rocks was slipping, and no matter how much he struggled, he couldn't lift Jim.

His body screamed at him to let go.

His heart screamed at him to hold on.

"Bones."

Jim's tone had changed to one of eerie calm. Knowing exactly what he was thinking, Leonard refused to look at him. "I've got you," he insisted, barely able to get the words out.

Whether it was pain or terror or both choking him up, he couldn't tell.

Come on, Leonard. Jim always dragged you to the gym for a reason. Do not let that be in vain.

But he knew it wasn't lack of muscle failing him right now.

"Bones, let go."

His grip on the rock had slipped to fingertips only, and he knew that if he lost that hand, he would plummet over the edge with Jim. "I'm not letting go," he snapped.

"Bones!"

Finally, Leonard looked down at him. His calm tone belied the terror in his eyes, belied the way he was still clinging to Leonard's arm. "I'm not taking you with me," he said.

"And I'm not going without you," Leonard shot back.

Jim gave him some twisted, grim facsimile of a smile. "Captain's prerogative, Bones. I love you."

Not giving himself another second to think, he jerked his arm, easily dislodging Leonard's weakened grip, and let go.

The sudden lack of weight sent Leonard reeling back like a slingshot.

Only the grip of enemy hands kept him from throwing himself back over the edge.

-LLAP-

Medbay was swamped with patients.

The ship shuddered, rocking from blasts from whoever was attacking them this time. Leonard hadn't exactly had time to call the bridge and ask – almost as soon as medbay had been plunged into the dull lighting and blaring alarms of red alert, the first patients had come streaming in. He had been running around in the controlled chaos that brought him alive ever since, triaging, shouting orders, giving reassurances, noting with satisfaction in the back of his mind every crewmember who came in a patient and went out under their own power, healed and ready to return to duty.

Every life saved reminded him why he put up with everything he hated about flying through the unknown dangers of unexplored space on a glorified tin can.

Though the battle had since calmed, red alert fading to yellow and the alarms going blessedly silent, the doors slid open, admitting another pair of crewmembers, one leaning on the other. "Chapel, go check them out," he said, focusing on the deep laceration he was currently closing.

Standing beside him, she glanced up, and promptly didn't move. "You may want to see this one yourself, Doctor."

"Nurse-"

"Doctor."

Interest grudgingly piqued by her insistence, he switched off his instrument and glanced up.

Jim smiled sheepishly back at him.

Damn it.

"Take over here," he muttered unnecessarily – Chapel was already plucking the tool from his hand and getting into position, bumping him out of her way.

Weaving around his staff, Leonard made his way to over to where Nyota was half helping, half forcing Jim onto a biobed. "What happened?" he asked, snatching up the nearest tricorder and running it over Jim.

"Nothing-"

"He was caught in the edge of an explosion," Nyota overrode him, silencing him with a fierce stare. "And refused to leave the bridge until he collapsed."

Leonard remembered the trio of bridge officers that had been carried into medbay about an hour ago, his heart skipping a beat as his imagination ran wild with images of Jim burned and bleeding before he clamped down on the irrational fear. His readings showed that, though Jim had cracked several ribs and there was shrapnel embedded in his slightly scorched thigh, there were no internal injuries or nicked arteries. "You'll live, you idiot."

"So I can go back-"

He snapped his mouth shut at the combined don't you dare looks of Leonard and Nyota. And, based on the way he froze when he tried to slide off the bed, wrapping his arm hurriedly around his ribs, it was also to keep himself from letting out a very undignified noise of pain.

Leonard took hold of his arm, carefully helping him settle back, and despite his gruffness, he let himself card his fingers through Jim's hair when the kid clutched his sleeve, momentarily giving in to the agony. "Gimme a sec," he murmured. "I'll get something for the pain, and then-"

"Doctor!"

A young engineer raced into medbay, eyes wild, chest heaving, and Chapel was at his side in an instant, resting a hand on his shoulder. "Calm down, Ensign," she soothed. "What happened?"

"My brother and his team," he gasped. "They were working on- on something, and it exploded. It's bad."

Chapel looked up at Leonard, and he nodded. "Grab a couple people," he told her. "I'll be right behind you."

She obeyed, moving with purposeful calm, and his people followed the ensign out into the corridor.

Leonard turned back to Jim. "I have to…"

"I know," Jim said, a thin smile not quite managing to mask his pain. "I'll live, remember?"

"I'll stay with him," Nyota promised. For all of her own sternness, she had yet to let go of Jim, rubbing his shoulder reassuringly. "He won't die on my watch."

"Good," he said, flashing her a look that translated thank you. "I'll be back."

"Can't wait," Jim grunted, leaning his head back against the wall. "Getting stabbed with hypos is my favorite time of day."

Forcing out a huff to cover his laugh, Leonard gave his hair one last ruffle and hurried to catch up with his team.

-LLAP-

Save the rhythmic beeps of the heartrate monitor, all was quiet in the hospital room.

Leonard sat at Jim's bedside, in precisely the same spot he had occupied for the majority of the last three weeks, just running his fingers through his hair and watching him breathe. He had come close to losing Jim before, but this time…

This time, he had lost him.

Jim's nose crinkled. "B'nes?" he slurred.

"I'm right here," Leonard soothed, never altering the steady pace of his fingers, steeling himself against the inevitable disappointment of hoping he would wake, only for him to fade back out.

Mere hours after what had appeared to be his successful return to consciousness, every alarm had erupted at once, warning of every system in his body rapidly shutting down. Leonard and the few other staff who had the clearance level to know exactly what had happened had managed to stabilize him, but he hadn't truly regained consciousness since. Sometimes he would shift a little, maybe even mumble a thing or two, but he had yet to open his eyes.

It was slightly better than when he was comatose, but not much. The world was too quiet without him, too still, and if anything, the intermittent stirrings only made him look even younger, even more vulnerable, as if he were once again the malnourished teenager he had been when life brought them together.

"Go back to sleep," Leonard murmured when his nose remained crinkled, wishing with all his heart he would do just the opposite.

"Don't wanna."

Though he didn't let his fingers still, Leonard's breath caught in his throat. It wasn't out of the ordinary for Jim to lean into his touch a tiny bit, but this was the first time he had verbally responded to anything. "Jim?" he asked hesitantly.

Jim's brows furrowed, and slowly, oh so slowly, his eyes cracked open, revealing the first sliver of that familiar vivid blue that Leonard had seen in a week. "Bones?"

"Take it easy," Leonard said quickly, suppressing the desire to leap for joy, settling for lightly cupping Jim's cheek and guiding his head around, feeling tears begin to well in his eyes as Jim finally, finally looked at him. "We nearly lost you again," he explained, his voice rough but not quite cracking.

"Oh," Jim said, his slurring easing into steadiness. "Uh… sorry."

Leonard couldn't help it – he laughed. It was that or cry, so he dropped his head and just laughed. "Would you quit being so damn adorable?"

"Nope," came the cheerful, albeit weak, response.

Shaking his head, Leonard looked back up, treasuring the tiny smile that greeted him. "You're a nightmare, you know that?"

"Mhm," Jim hummed. His eyes were already drooping, and he nestled closer to Leonard's hands. "'M cold."

"I'll turn the heat up," Leonard offered, starting to stand.

In what was probably the only spurt of strength he had in him, Jim tugged his arm over to hook his fingers into Leonard's sleeve. "Don't go," he pleaded, eyes widening slightly in panic, in the familiar fear of abandonment, in the new fear of death lurking in the shadows, waiting to drag him back into the dark abyss.

Leonard sat, taking Jim's hand into his and squeezing. "You ain't getting rid of me that easily, kid," he promised quietly. "And I sure as hell ain't letting go of you."

Jim leaned forward, resting his forehead against Leonard's arm. "Don't wanna sleep," he mumbled. "I keep… not waking up."

"Come on, kid," Leonard scoffed, surprised to realize that his bravado came from a genuine core of confidence. What a miracle a few moments of hope and joy could be, he supposed. "You and I are both too stubborn to let you stay down for long."

Jim huffed a laugh, glancing around the small room, lingering over the readouts that, a mere three weeks ago, hadn't registered a single sign of life. "Guess we are."

"Get some rest," Leonard encouraged. "I might have Jell-O for you when you wake up."

"Red?" he asked hopefully.

"Do you eat anything else?"

Jim snuggled a bit closer, his eyes drifting shut. "Everything else sucks."

"Blue doesn't."

"Yes, it does."

Leonard shook his head. "Haven't you learned not to argue with your father by now?"

"You're barely six years older than me."

"True, but I'm pretty sure the law stopped caring about that when I signed the custody papers."

"Whatever."

His voice had all but petered out, exhaustion taking over. For once, Leonard got to let himself make a father's decision and shifted to gather him close, tucking the blanket more securely around him. "Good night, kid."

Jim's voice was barely above a breath, contentedly fading into sleep. "Night, Dad."

Leonard smiled at the rarely used name, watching Jim's breathing ease into sleep's steady rhythm. But this time, it felt less like watching a miraculously revived survivor cling to life, and more like being back in the early months of their relationship, when Jim had gradually stopped flinching at the slightest unexpected noise, when he had started sleeping through the night, and when he had finally trusted Leonard enough to let himself fall asleep on the couch beside him, sprawled out and snoring lightly, scarcely disturbed when Leonard got up to throw a blanket over him.

I love you, kid.

Time, he knew, would've made these moments few and far between whether Leonard had joined Starfleet or not. The only difference from his expectations upon arriving at the Academy was Jim's sudden rise in rank, both allowing and requiring them to stay by each other's sides day in and day out, yet preventing them from simply being father and son, or brother and brother, or even just friend and friend. They had their duties, and more often than not, those duties would call for them to hold back on this bond that had helped Jim through the remnants of his broken adolescence and Leonard out of the remains of his broken marriage.

But if suffering through a million moments like that meant they got a moment like this every once in a while, well, maybe Starfleet wasn't the worst place Leonard could've ended up.

A/N: (If you wanna know how Jim survived that fall, there was a ledge. Probably broke a bone or two, but hey, he didn't die. I might actually make that scenario a full fic at some point.)