They were two-thirds of the way through the upward loop they were making and Leonard was starting to regret he ever thought he could do this. Each footstep was agony now, the insistent burn piercing through his nerves like a hot poker to the gut. Maybe, just maybe he could deal with the pain, sort of grow numb to it after a while, but the real issue was that his strength was nearly gone. They had rested once more, but Jim said they shouldn't linger and waste daylight. Once Leonard had shrugged off his pack, free of the weight that bore down on him, it had been all he could do to stay awake.

Jim was rambling on about some epic backpacking trip he and his fellow rock-climbing enthusiasts (i.e. other people with no sense of self-preservation) took to Alaska, or maybe it was Alberta, Leonard wasn't sure. He had stopped paying attention about an hour ago, and quit talking a half-hour before that to save his breath. He wasn't trying to ignore Jim, it just took all of his concentration to take each step forward.

One foot in front of the other.

Right,

Left.

Right,

Left.

Jim's prediction that the temperature would change once the day progressed had turned out to be correct. It was warm enough to start melting the snow and dirt into dangerous, slippery muck. Some landslides had already occurred a stone's throw away from them, so they had to be careful where they stepped. Jim was doing this instinctively, pressing ahead with a drive Leonard didn't have, and Leonard found himself sliding backwards in the mud more often and falling further and further behind. He crossed his right arm over his torso and clamped a hand over his injury, trying to keep the pain at bay. Muscles and lungs burning with exhaustion, and sweat rolling into his eyes, he took one more tentative step and called for Jim in a broken voice. The captain turned around mid-sentence, trailing off when he saw how much distance was between them.

"-Bones? What's up?"

Jim started to double back and Leonard staggered forward, trying to meet Jim halfway, but then his body decided it had finally had enough. With a whimper, Leonard keeled over into the cold, muddy slush at his feet. Everything went grey for a while, then he distantly heard his nickname over and over, and felt Jim slap his cheek until it began to smart. He slowly came around, reassuring Jim that he was ok, but Jim was having none of it.

"You should have told me how tired you were," Jim said, sounding indignant and equally frightened. Loosening the straps of Leonard's pack, he freed the doctor and lifted his torso out of the mud. Cradling him in his lap, Jim narrowed his eyes at the arm Leonard had tightly wrapped around his torso. "Why are you guarding your stomach?" he asked. Leonard struggled to find the strength to even answer him.

"I've got a stitch in my side," he rasped.

"You know, what I don't understand is that I searched and searched for that head wound and never found it. I went through your entire head with a fine toothed comb, Bones, literally, and I still have no clue where all that blood came from." Jim impatiently waited for Leonard's explanation… or confession.

"I laser sutured it so you never saw it," Leonard said weakly. The answer was the truth, if about another part of his anatomy.

"You still reek," said Jim, wrinkling his nose.

"Well you sure don't smell like a bed of roses yerself!" Leonard growled.

Baring his teeth, Jim exclaimed, "Like blood, Bones! You smell like blood!

Locking those aggravatingly blue eyes with his- and yes, aggravating, because how dare they be so damn blue at a time like this? How dare they?- Jim reached down and pried Leonard's arm back. Leonard tried to resist, but didn't have the strength to fight him. Jim forcefully pulled down the zipper of Leonard's jacket and pushed both halves of the garment out of the way. Focusing on where Leonard's hand had been, Jim carefully examined him, pressing his fingers into the left side of Leonard's stomach, then gradually moved lower, fingertips probing all along the way. Jim stopped when Leonard contorted in pain. He pushed up the blood and sweat-soaked thermal and saw the bandage peeking out from behind Leonard's belt.

"What is this?!" Jim demanded angrily, and Bones faltered.

"I was hit by some debris, okay?" More like the shuttle caved in on him, but he wasn't about to tell Jim that.

"You've been injured this whole time and you didn't say anything?!" Jim was livid and practically shouting at him, obviously more panicked than enraged, but Leonard still automatically flinched back, his mind going blank. He opened his mouth to speak, but the words wouldn't come out. After Jim had had enough of listening to Leonard stammer unintelligibly, he made a frustrated noise and snapped, "Where's the regenerator?"

"You can't use the regen on it," Leonard finally blurted out, trying and failing to push Jim's hands away as the other man peeled back the bandage. The look of horror and sympathy on his friend's face as the full extent of the injury was revealed made Leonard feel shame in the pit of his stomach.

"God. Just- why not?!" Jim 's fingers lightly traced the jagged scar and the deep purple and greenish bruising, as if he could erase all the hurt with sheer willpower alone.

Leonard took a shaky breath. The truth was that the regen would work on the dermal and muscle layer, but it might make his internal injuries worse. Organs like the small intestine and the bladder were made of cells that regenerated at a much faster rate than muscle or skin. They could seal themselves off, flower into dense bouquets of tissue, or fuse with the peritoneum or other organs. He decided that Jim was better off not knowing the specifics. "You'll fuse the organs underneath. It's complicated. You need specialized equipment that's only available on the ship. I did what I could for now and it's crude, but I stopped the bleeding."

"This looks painful. You shouldn't be carrying anything," Jim stated, clutching his head in his hands in agonized frustration. "Oh, Bones… you should have said something!"

"Hurts like a bitch but I'll be okay," he lied. "And you can't carry everything yourself. It's just not possible." Jim's defeated silence was validation that Leonard was right. He watched as Jim carefully put the adhesive pad back in place. Leonard laid a hand on his arm. "Jim… I'm so tired. I need to rest. Please. Then we can climb the rest of the way."

"Okay." No resistance. "I'll make you more food. You need to eat a solid meal."

"Before you do that, hand me my medkit, will you?" Leonard requested. Jim located the strap around Leonard and pulled the medkit back around, placing it in his hands. The doctor took out the hypo and fumbled with it, giving himself another dose of the painkiller. Then he unclipped his medical tricorder from his belt and did a basic assessment scan, and the thing immediately blinked red and screeched in warning. He quickly shut it off, but not before Jim noticed.

"What is it? What'd it say?!" Jim asked, looking down at him in alarm.

"My blood pressure is too low," said Leonard. "Not critical, but low enough to be a concern." At least, not critical yet, but it was proof he had internal injuries that he was aggravating with all this hiking. It was too bad that he and Jim weren't the same blood type. There were a couple pints of blood substitute in the first-aid kit, probably not enough to sustain him until they were rescued if the Enterprise took their time. Still, it might be prudent to use one before his blood pressure bottomed out and he went into shock.

"Jim, you're gonna have to play field medic for a few minutes," he said. The captain went rigid and a strange expression crossed his face. Leonard realized it was self-doubt… something he hardly ever associated with Jim. "Look in my pack for the first-aid kit. There should be some bags in there labeled PFBOC." Obeying, Jim quickly produced the first-aid kit and pulled out a plastic bag full of milky fluid. "See that foil packet attached? Pull the tab and there should be a sterile IV line inside with a device at the end. It's meant to be user friendly, so you don't have to worry about sticking me with any needles yourself."

"Wait, are we- we're putting this shit in you?" Jim asked, making a disgusted face. "What is it?!"

"Artificial blood. My system's all outta whack because I've lost too much blood. You're going to help me do a transfusion."

"I-I can't," Jim said, going pale.

"Sure you can. It's easy. My daughter knows how and she's in elementary school."

"But she's a McCoy," Jim argued.

Leonard glared up at Jim, raising his eyebrow for emphasis. "Medicine doesn't have to run in your blood to be able to do this, Jim. Now stop being a worry wort and get it together!" Jim nodded, setting his jaw. "The strap goes around my arm and the device goes on the inside of my elbow. Tighten that...it's like a tourniquet- and press the start button. It should give you instructions." Jim turned the watch- sized device on and waited.

"Mapping vessel structure," said a pleasant, neutral-toned AI. "Searching for optimal insertion site. Target vein acquired. Adjust the cannulizor until target matches up with overlay on the screen. Adjust the cannulizor. Adjust the cannulizor. Adjust the-"

"This thing is kind of annoying," Jim muttered, incrementally moving the device around until it chimed.

"Correct placement over target vein achieved. Scanning. Confirming correct placement. Sealing." It whirred and became airtight on Leonard's skin. "Hold bag higher than insertion site and ensure there are no kinks, loops or tears in the IV line." Smoothing everything out, Jim held the bag in his hands. He glanced down at Leonard nervously. The device spoke again. "Cannulizing now." Leonard flinched at the sharp sting in the crook of his arm and then the cold sensation of the blood substitute flooding his veins. Breathing deeply, he closed his eyes and soon began to nod off. Jim shook him awake.

"Hey, don't pass out on me again! What do I do now?! How do we know it worked?"

Leonard grinned weakly. "It'll say so. Obviously. And it should show my blood pressure on the screen. Closer to 120 over 80 the better." He patted Jim's arm. "It'll disengage by itself when it's done. Relax, there's nothing to be worried about. Just let me sleep for a while."

Jim looked anything but relaxed. He watched the pale fluid drain out of the bag between his fingers through the IV line into Leonard's arm. "We should have done this before we left the shuttle," he said ruefully, but Leonard didn't respond. He was too exhausted to keep his eyes open.