For the younger folks unaware, there was a TV show back in the 1980s called St. Elsewhere. There was a little boy on the show, and in the very last scene of the very last episode, a pan-out on the (hospital, I think?) was suddenly shaken around, and we learn that the entire series had taken place inside a snow globe belonging to the real version of that boy, who had autism, and all the characters and events of that show were things he imagined while looking at it.

But TV executives like crossovers as much as we fanfic writers do, and thanks to actors guest starring across other shows, a whole lot of television series are connected to St. Elsewhere, which means they are also part of that autism-powered snow globe dream. There's a list current as of 2016, where we find that the PPC is also part of that boy's dream, thanks to our forays into the Buffyverse, Battlestar Galactica, CSI, the Whoniverse, Firefly, General Hospital, Heroes, M*A*S*H, NCIS, Star Trek, Stargate, Supernatural, Warehouse 13, and The X-Files.

So: does that mean all the other universes the PPC has entered are also part of the snow globe dream? And since so many recruits come from World One . . .

—doctorlit, intentionally ridiculous