You never really get "the call" or anything. You simply realize it's going to happen when a fact-checker (for me, the always fabulous Robert Scheffler) sends you an email requesting sources and you start the back-and-forth negotiation on specific factual points (e.g., I remember reading something to this effect and put it in the piece, but Scheffler can only find a cite that says something to that effect, and then we negotiate the most reasonable statement based on easily proven/obtainable sources). The negotiations only pertain to stuff I've pulled from memory, as the vast majority of cites in any piece come from interview notes or easily accessed sources that I simply turn over to Bob at the start, letting him find all the references on his own so as to make sure I didn't copy anything down incorrectly--and there are always such errors/typos (e.g., I remember and write "domination" and it was really "dominance" in the citation). Small stuff, but Esquire is suitably anal about all that. If I said it was a sunny day in such-and-such a place that afternoon, they'll actually check to see if that was true!
Anyway, fact-checking done and now I'm just going back and forth with Warren on length--the inevitable trimming of that "tail" that extends a page too far.
I wrote this piece somewhat backwards: researched and wrote the big-picture part and sent it to Warren, and then researched and wrote the more specific parts, and then wrote the material that stitched the specific to the big-picture. Typically, in terms of production, I'll go specific to stitching to big picture (or sheer reporting to unearthed themes to what-does-it-all-mean?), but that's how our original conversations went (I mention the big-picture thing and Warren says, "write that up for me," and then he tasks me on the specifics, which I write up, and then we argue/brainstorm/whatever about the stitching). So the original text order from me was big picture, then details and then stitching (which is usually an awkward progression for the reader), and Warren eventually shifted it to specifics/big picture/stitching, or sort of a set-up, larger context, and then how the two clash (which is nice and more the norm for a magazine article--as in, draw you in, contextualize, and then resolve).
So we'll see it on shelves come early January.
And yes, I'm very happy with the piece. I was very surprised to bump into the theme and thought it turned out nicely.