Sherlock faked his own death and went off on a lark to hunt down the rest of Moriarty's web, but it never occurred to him that John wouldn't just eventually move on. It never occurred to him that John, grieving and vengeful and teeming with the military badassery that he's usually content to hide behind his jumpers and polite smiles, would decide to take up arms again and go after Moriarty's empire himself. And of all the things they've seen on out on the trail, the last thing either one of them expects to find is the other.
I'm up for playing either Sherlock or John. Expect epic action, gen or eventual slash, probably inadequate wiki research and more ideas than will ever make it into words, let alone scenes. Long-term would be awesome but I'm just as happy with something short and sweet.