Anyway, the last episode (entitled "The Ghosts of Christmas Future") was directed by Greg*, who normally plays Drew. It was a brilliant, high concept episode involving a very focused application of time travel. We started the episode in the middle of an oh-my-god-we're-going-to-die brawl in the we hours of Christmas Eve/Morning. An established NPC demon with time travel powers was available to facilitate a desperate evacuation to 12 hours prior, whereby we had to relive the previous day's events as our past selves and struggle with our future selves to find a way of winning the battle once we had caught up with real time.
I had been hoping to run an episode something like this for a while because it seemed like one of the few genre TV tropes that we hadn't used yet. But as I was still trying to figure out how to make it work, Greg beat me to the punch.
And it did prove to be a small wonder of organized chaos. Greg allowed us a great deal of narrative power to define how we actually ended up in that fight. A rule of time travel (for the episode if not the entire series) was that we absolutely could not change history. So when we declared that our future selves "remembered" something from the previous 12 hours, we miraculously managed to make it happen for real.
Of course, Erik instantly remembered the he had received a call from himself (thus kicking off the whole series of events). Erik can't keep a secret, even from himself. The conversation between future Erik (played by me) and past Erik (played by Greg) was one of the highlights of my RPG life.
Now the Greg has done this episode for Buffy, I can't imagine doing it again for this particular campaign. *But*, Oh My do I want to try something similar in the next game that I run! And it doesn't have to be time travel. This episode also served as a model for how to one of those "start the party in a cliffhanger and explain how they got there before the resolution" type games.
* By some strange coincidence, Greg has run most of our Christmas episodes. Weird.