Humans were never meant to live as long as O5-13.
Turtle is supposed to live this long. I could be a turtle man.
A rare smile crept across the usually sullen face of -13. The man nearly attempted to hide the smile before realizing that he was alone. No more hiding. There would be no use anyway. Something had changed. -13 was not sure what it was yet, but something was different. The ache in his bones had subsided, a rare occurrence. -13 hadn't felt so good in years.
Every fiber of his being told him that he was sitting on a familiar beach. But of course that was impossible. -13 hadn't sat on a beach for as long as he could remember.
A childhood memory?
No, impossible, and if it was the case, he was going to need to make a call to up the dose of the antimemetic cocktail he made for himself everyday. "An O5 must have no past, and must always look to the future." They had agreed on that when they made the creed with each other.
O5-13 took a long sip of the vodka he didn't realize he was holding. A flood of memories washed over him with every sip, drinking with friends in college, taking a swift, teasing sip of a drink held by some lady friend of his, spluttering all over the table when his father had introduced him to the drink. -13 closed his eyes and attempted to think of his father. What had previously been a blank slate had been replaced with a strong, tall Russian man, an intimidating frame, other than his hard but caring eyes.
-13 tried to take another sip, only to come up empty.
No matter.
His childhood had come back to him. Living with his father, many times in poverty, but never in sadness. No mother. Possibly dead? Didn't matter. The brief distraction had been nice, but O5-13 still did not understand his situation. Standing up, he moved towards the crashing waves of the beach. As he approached, the waters calmed, and seemed to freeze. A tentative step onto the water revealed that he was able to walk on it, despite small shoals still popping up around him.
The sunset was ahead of him. With nowhere else to go, he stepped forwards. The sun got larger as he approached, like a backdrop on a painted set. He moved forwards until the rest of the pink sky had disappeared, leaving only the yellow of the sun. -13 stuck his hands out towards the yellow, revealing that it was also solid. A sliver of silver caught his eye, and he noticed a doorknob.
Twisting the door open, O5-13 stepped into the sun.

O5-13 walked down a set of stairs in what seemed to be an airport. Everyone around him spoke English, a language he was somewhat unfamiliar with. Several people waited at the bottom of the stairs with signs. Scanning the signs he picked out the only one in Russian.

Добро пожаловать Врац ██████

-13 could not tell what name was on the sign, just that it was his. Attempting to look at the sign gave him a headache. The man with the sign lit up with recognition upon seeing -13 descending the stairs.
"My name is Dr. Misha Pajitnov." said the man in perfect Russian, "I attended one of your lectures on parapsychology before I got transferred to an American site. You have done wonderful work."
"Thank you, but could I see some identification?" -13 responded somewhat curtly, "I didn't live this long in my line of work by getting into cars with people who just claim to know me."
Dr. Pajitnov handed a piece of paper with an order from the Site Director and an ID badge. As -13 looked at the paper, it transformed in front of his eyes, as the scenery changed from a grungy airport to some sort of lab. The documentation regarding his processing to a new Site had been transformed into a research paper. A door opened behind him.
"Still writing?"
A man younger than he, yet his superior, stood in the doorway.
"Doctor Buchanan, what a surprise to see you here so late." -13 asked bemusedly, "When do you usually leave? Four hours early or five?"
"You got me there. Site Director privilege I guess. Come with us, we're getting drinks. Leave the papers to the Junior Researchers."
"Can't. Working. Too many anomalies, too little time."
"You'll burn yourself out this way. When was the last time you had a drink?"
"Years. Don't plan on drinking again. Too much money to just waste time."
"Well if you change your mind, pretty much everybody will be down the road. I guess you'll be hanging out with Site security again tonight."
"I like them. They don't talk as much as you."
"Cheeky. I could fire you at any time you know."
"You wont. You like me too much."
The young man rejoined the other researchers, and finally left -13 alone. O5-13 turned back to his previous paper.

OFFICIAL O5 SUMMONS

Looking up from the paper, -13 found himself in a conference room with several other people.
"What was I called here for?" -13 asked, concernedly, "Is there an issue?"
"We… have had some issues with your home country." the man at the end of the table asked, "We do not display the members of the O5 council to everybody, and unfortunately our member from the Soviet Union has passed. We need you on this council or we risk… complications."
"Forgive me for my rudeness but am I to assume that I have been some sort of back-up all along?"
"Don't flatter yourself." a woman two seats away from him said, "We have had several other candidates. However, you outperformed the others, so congratulations. Welcome to the O5 council."
"Is that… it? Do I get a choice?"
"Of course. You can refuse and pass up a chance to alter the fate of the entire world, but you wouldn't make our decisions harder would you?"
"I like my Site though. I have a lot of work going on there. The people are good."
"How naïve. Security, please take him to get amnestized."
"Is this necessary? I don't even know where I am right now and I'm sure I'll forget your faces."
"Do you think we got this far by being careless? Could you please take him to room 13?"
"Yes ma'am. Standard or special?"
"Special please. This man is very important."
-13 was escorted to Amnestization Room 13, and placed into a chair with straps. The straps were placed around his wrists and ankles rather roughly.
"Whats the order?" the woman asked over the intercom.
"Special order, no past, when he wakes up, tell him about his job and such."
"Gotcha."
"What do you mean? She said to just clear the last day or so. Hello?"
As the first syringe went in, the room around him became the conference room he was in earlier. He sits in his chair and waits.
Another day, goes by, this time he has to resolve a tie. He waits more
His skin grows wrinkled and gray. He grows older, usually sitting in a chair, waiting to have to make a decision.
They give him a treatment so he ages back a bit. The mind stays old but the body becomes new. He sits in the chair and waits.
A snapshot of his decisions over the measure of seconds. He ages forwards, sometimes backwards, sitting in a chair, just waiting until he has to make a hard choice.
He makes a decision to make himself immortal. Wasn't even a difficult decision, or a tiebreaker like it tended to be. A unanimous vote to escape death's cold grasp.
And eventually, the chair he sits in is a beach chair, with a vodka in his hand, older than he has ever been, but feeling as young as can be.
I imagine I should wake up sometime soon. Would be nice to stay here a bit longer though. Does this happen every night?
The area around his periphery darkened, moving in gradually.
My name is-
His thoughts were interrupted by the dark finally closing around his vision.The last thing he could see was the sun setting across the horizon.

O5-13 lays on the ground. An unkillable man is dead, as are the 12 other unkillable people. He had been shot several times. The light had faded from his eyes, his immortality stripped from him. A life lived many times over. An old man, older than what should've been possible. A man who had worked with impossibility every day until it became mundane, just a job.
His name was O5-13. He has no other names.