In rewatching, it becomes clear to me that what I took as a sudden confounding turn into sci fi the first time I watched it has actually always been the mythology of the series. Of course, with all this sci fi stuff running through it, it would be ridiculously easy to crossover with Doctor Who. That is how I am justifying the more perplexing parts of the show. It's a Who crossover that just hasn't had the Doctor show up in it yet.