Life Out of Death
Jack O'Neill was staring almost uncomprehendingly at Thor, his gray little buddy of almost fifteen years who all of a sudden was neither gray nor little. That --by itself-- would have taken some getting used to but it was nowhere near the whole story. The thing was that when, almost ten years earlier, he had agreed to Thor's strange request he had never imagined that this day would come... he had never imagined how much it would hurt. It wasn't a permanent solution and they both knew it. It was only a stopgap measure intended to keep the Asgard alive for a few millennia but it was probably going to be enough to save them. It was probably going to be long enough to enable them to find that elusive permanent solution.
He still remembered when the request first came, shortly after the whole incident with Loki and his clone. It was then that they had become aware of the Asgard's problem. It had been a desperate request made at desperate times and --truth be told-- when he had acquiesced he had never really expected anything to come out of it, he had never expected that Thor's desperate request to be allowed to study some old bones would actually pay off.
Thor, his gray little buddy who all of a sudden was neither gray nor little.
The bones had held the key, they had held the DNA sequence that had been the Asgard's Holy Grail, the one that had enabled them to transfer their consciences to a human body.
It was strange to think that he had agreed only because Thor's request had meant that maybe, just maybe, something could be saved out of what had been a senseless tragedy, that he had agreed only because agreeing allowed him to hold on to the hope that maybe somehow life could come out of death. The thing was that, while he had agreed, he had never really understood how much it would hurt to see him standing there, how devastating that life out of death was going to turn out to be for him to witness.
He was standing there, right in front of him, his former gray little buddy who all of a sudden was neither gray nor little, his gray little buddy who all of a sudden was looking a lot like he once had... only slightly different. The one in front of him was a clone but unlike Loki's botched attempt it was not his own clone.
The one standing in front of him was Thor only it wasn't Thor. It was Thor who was looking a lot like O'Neill himself had some thirty years prior. It was Thor, who all of a sudden was looking like a healthy young man in his late twenties, as all Asgard now did... it was Thor who was now wearing Charlie's body as if it were his own.
Authors notes: Okay, this little story woke me up at 4:00 am and demanded to be written.
I know the idea that O'Neill's descendants hold the key to the Asgard's reproductive problems is hardly original, in fact I admit Ive read several stories based on a similar premise, however those are usually either an excuse for a Jack/Sam, Jack/other story or crossovers in which he finds out he is the father of a character from a different fandom... I have never found one in which Charlie is the key.