That's pretty much what happened a couple of nights ago.
I was stuck, as I mentioned, deep in the Blargs. So I dug through my folder of unfinished or unedited manuscripts, where I found "The Last Dragon Dancer," a story about a man who can communicate with dragons.
I had originally planned to submit this to John Joseph Adams' "Way of the Wizard" anthology open call, but I wasn't happy with how un-wizard-y the story felt, so I left it alone and tried my hand at something else...nothing else worked out, and the deadline for the anthology reading period came and went, and "The Last Dragon Dancer" went into the trunk.
After re-reading it, I don't know why. Most of the story is very well written, and only loses steam at the end, where looks like I was trying to rush it. If a story can stand up to a reread months later, I take that as a good sign that it has potential. To contrast, my "Magic Words" story did not stand up to a reread, and even a good hard editing didn't really leave me all that confident in it, so it's safe to say that the months-removed reread is the ultimate test. Someday, if I am ever lucky enough to do this for a living, I will never submit a short story anywhere that hasn't aged on the shelf for at least six months.
Anyway, the last four subchapters to the story read like a detailed summary rather than a story, so I was struck with the idea of fleshing them out without having to necessarily reinvent the wheel; I merely expanded upon the ideas already there. I'm nearly finished (only a few hundred words to go, I think) and then it's submission time.
Luckily, with the changing of the calendar to September, many markets that close their doors for summer sabbaticals reopen around this time, so I have many more options today than I did a week ago.
I'll let you know how it goes.