The time traveler long suspected that becoming immortal was a big moment, a lightning strike. The time traveler even hung around the immortal's mother during the pregnancy.
All in all, the time traveler visits the immortal as a fetus, a baby, a child, a teenager--more than six hundred times. Members of the immortal's tribe think of the time traveler as a trader. No other woman gets pregnant during this time, no other children are born. Then, when the immortal is still young, members of the tribe start to die off. Not odd at first, as it is pre-cities ancient times, but the time traveler scans the dozenth to die and discovers a cancer these people shouldn't have yet, the same cancer that is strangling the time traveler from the inside out.
It's the radiation leaking from their long antiquated time machine, the time traveler realizes with dawning horror. They've killed these people, orphaned the immortal. Made the immortal through some fluke. Six hundred little moments, adding up to one when the immortal takes an arrow to the heart, then gets back up, bewildered.
It makes the time traveler vomit.
The time traveler takes the immortal from their tribe when no one is left, makes sure that they get to a farm and pays the family to care for them, and does not visit any version of the immortal again for some time.
--
Three thousand seven hundred and eighty seven years after the time traveler storms out for the second time, the immortal comes home to a dusty book with papyrus pages. It's written in a language the immortal knew once but has long since forgotten, and has a note.
Remember you mentioning it was one of your favorites.
The immortal smiles and runs a hand over the pages, reminiscing without reading, trying to imagine what sort of story was within that must have captured their imagination enough to mention it to the time traveler.
Is this before or after the time traveler knows?
--
"How did you become immortal anyway?" the time traveler asks again, fear wrapped about their voice like a thorny vine.
The last time the question is asked to the immortal, they are old, frail. No longer mobile on their own. Dying. Nothing lasts forever. "Must... we discuss... mortality?"
"Nothing lasts, except for you?"
"Heh. I'm not lasting much longer... s'good m'tired"
The time traveler fidgets. "I--I mean, I'm sorry--did you always--"
The immortal raises a hand, shushes them, and gestures at the floor. It's been so long that the immortal cares not for attempted apologies.
They sit down beside their friend's wheelchair, face towards the looking glass.
There is no more life on Earth, not anymore. Something to do with the sun, something to do with the ozone layer, something the time traveler never bothered to learn, but humanity can still watch storms swirl across continents the time traveler cannot recognize from space stations. Stars glitter around it and the time traveler doesn't have any context for this moment, it's too far in the future, but when they look up at the immortal their eyes are shut and so the time traveler huffs out a small sigh. It's not a bad place to rest, to die.
"Ok," they say. "Maybe you did have a point."
The End.
