The first part of my three-parter is ready... A few of my previous stories were de facto two-parters (In Harm's Way/Behind the Eight-Ball and Hammer & Stone/Consequences, IMO), but this one is specifically being written that way.
I've had this concept planned out as the 'season finale' since about chapter 6 or 7 of "A Voice...", honestly. It was just a matter of putting everything into play for it, first.
Time travel, even relatively tame time travel such as this, is always fun, and I think I've hit upon at least a reasonably uncommon method of facilitating it. Thanks to  eightane for some pieces of advice! There's one part of the sequence that was written specifically off of his information.
While I said I'd had this planned, there was still much of it that came entirely on the fly, from my research. The identity of the Knight, for instance. All I'd known until a few days ago was that he was an Outlander, and probably an exile or traveler. I never *guessed* that he'd be who he actually was, yet it fits so well that I can't say no.