I dug around in all the requests for SG-1 crossovers, since I wad hoping someone else had asked about this, but no dice. It was set pre-series for both shows. John Winchester came to Colorado Springs hunting changelings, and after he killed them he tried to return all the children to their homes, using missing persons reports I think, but couldn't find one boys home or family. So he ends up keeping him. It turns out that the boy is Charlie O'Neill. I can't recall anything past that. I don't think it was very long, and it might have been WIP?
Also, can anyone rec me any well written 'John adopts a crossover character' fics? Especially any that go past the first three seasons? (I'm reasonably sure I've read all thr BtVS Xovers, though!)
Good example of what I'm looking for: The Book of Darcy by lforevermore (http://archiveofourown.org/works/4599903
Any thing but wincest is fine!
Please no AUs where the supernatural doesn't exist.