sailing the fingers of the dragon

Hmm, I'm not actually sure this would really fall under doppelcest. You know the basic premise of the Doctor, that he regenerates bodies instead of dies? Romana is of the same race and does that as well, so Romana I/Romana II isn't really doppelcest (Romana I being the brunette in my icon on this post and Romana II the blonde in my icon on this comment). Although Pandora is an entity who takes over Romana I's body at one point, so I suppose there could be something there. And there could be something if the woman on whom Romana II based her appearance comes back. (Who fandom brings the crack, oh yes it does.)

...short answer: I will point you if anything resembling doppelcest does happen. *g*