I had a dream last night that was layer on layer of narrative. It would be hard to narrate it in spoken words since I'd just end up getting lost, but here is an attempt at it. I purposefully did not look up any references.
My wife was pestering me about all these calls she was get getting on her cell phone about a job offer for me from the CIA. I finally returned the call and took the job. After spending a year of intensive study learning Arabic, my first actual assignment was from a more senior analyst to explain an obscure reference to the wife of Hercules in some Taliban propaganda piece. By chance, I found a reference to what it was talking about in the apparatus of a text of Diodorus Siculus. It quoted a line that the editor excised as an interpolation. It said that after his death, Hercules' wife (I confess I can't recall who he was married to at that time) married a giant. It only occurred in a single ms., an edition made by an Italian humanist just a year or two before printing was developed (I have no idea when the first Renaissance edition of Diodorus was made). The ms. was well known, and he says the texts he consulted in the introduction and none of them had the spurious line so this fellow must have added it for some reason. I looked at the accompanying Latin translation and there was a two page long version of the story, which I could never get a firm gasp on in the dream, but it was compounded of common Indo-European mythological motifs.
By some process I can't reconstruct out of the dream, I became aware that there was a translation of Herodotus made during the little Renaissance from an Arabic translation (I am fairly certain no such text exists), and this had a version of the story (much shorter--about half a page). So I looked at the Arabic ms. tradition of Herodotus and it turned out that this story was pretty common in them, but they have never been consulted by Western editors of Herodotus. None of them had even been printed, but many of them had high resolution photos published on the internet now (again, I have no idea if Herodotus was ever translated into Arabic).
So, our original editor of Diodorus must have known this story from some Arabic text and, triggered by a mention in Diodorus of Hercules' funeral, added it in, presumably because he thought it was "true" and he was just correcting the historical record. A key element of the dream is that I was working on the internal report for the CIA, I was at the same time writing a publishable article on the topic.