When he was administered the serum that turned him from John Grimm, human Reaper, into Reaper, killer of monsters, monster himself, it was assumed that it had made him into the same super humans they were digging up. And with that transformation, it had made him better than he was before. Better... stronger... faster... He was the hidden Six Million Dollar Man. And because he was hidden, he had to test every bit of survival instinct that he had to ensure that the world thought there were no survivors from the Mars quarantine.
When he decided to reenter the world, he had to work to hide his physical advances and instead push his mind to its limits. One wrong move and his years of secrecy would be one big waste. He didn't care how much "progress" humanity had made since he was a kid. Any illusion of freedom he had would be stripped once they found out what and who he was, and the rapid advances in technology weren't helping him hide. When the tricorders were standard issue for any self-respecting doctor, he was just one scan away from sending off glaring alarms to anyone who knew basic genetics.
Sometimes he really hated how the world kept pushing advancement on him. He tried leading simple lives. He went from soldier to deadly nomad to small-town Georgian doctor, but still complications kept following him, trying to turn him into something he never wanted to be. If they found that 24th chromosome he tried so desperately to hide, he would no longer be Leonard McCoy, jaded man with a heart of gold and a penchant for swearing. He would be John Grimm who was masquerading as Leonard McCoy, the soldier who disappeared at the disastrous quarantine on Mars in 2046 that left no survivors and no paper trails.
But as advanced as the world was, fooling it was almost painfully easy. He had seen the technology advance over years to the point where once he had taken apart one of the tricorders, he knew exactly what made everything tick. All he needed was a simple watch, on him at all times. It was his grandfather's if anyone ever bothered to ask why it never left his wrist. As long as the watch was always on him, and as long as no one ever noticed the small electric pulse it gave off, he would appear completely... utterly... average.
He grinned to himself.
He not only created a fake identity, but he created an entirely new genetic marker, as unique as if he were an entirely different person.
If only Sam could see him now.
"Does it ever bother you that you could've spent your life looking in a microscope instead of a sniper scope?"
His grin faded.
He shoved what-ifs to the back of his head.
No use thinking of what was already gone.
Jim was a Shakespeare fan, apparently, though you would never think it looking at him. When Bones thinks about it, he's not really surprised. He knows how dramatic Jim can be. The fact that Jim would spend any free time reading was what surprised him. He didn't know the kid had the patience.
It's three twenty in the morning and they just left the bar, Jim's arm slung around his shoulder and reciting Hamlet. Bones goes back into the habits of his first life, cataloguing potential threats, potential weapons, and Jim raps him sharply on the head and asks if he's listening to him. What he's saying is important, really, because Bones is his Horatio, his main 'squeeze', and Bones wrinkles his nose in annoyance, but then Jim goes to a dark place, and Bones can tell that he's thinking about his dad, and starts quoting Hamlet again.
"If thou didst ever hold me in thy heart, absent thee from felicity a while, and in this harsh world draw thy breath in pain, to tell my story." Jim holds out his hand dramatically, and they stop walking drunkenly into the night and instead just sway.
If he were the sort of man to talk about feelings, he would talk to Jim about his father, about no-win situations, and about finding his own destiny and all that crap. He might as well tell Jim that he's going to live forever, so if Jim ever feels like needlessly dying when Bones is perfectly content in taking his place in whatever dangerous situation he's involved in, then Bones is also perfectly content with beating the shit out of him.
"That's my middle name, you know." He says, instead, desperate to distract Jim, taking a swig from the bottle he is no longer considering as a potential weapon.
"Felicity?" Jim asks, delighted.
"No, dammit." Bones colors around the ears, "Horatio."
"Perfect! Perfect, perfect, perfect." He slurs, cackling, "Bones. Bonesy Horatio McCoy."
"And James Hamlet Kirk." Bones grumbles.
"Tiberius, actually, young Horatio. Like a lion. Or a tiger thing." He growls at Bones for good measure.
"Right, cub, now lets get you back to your den."
Three months later, when he's updating his records, no one says anything when his name is now Leonard H. McCoy.