Alex: How did you get to do Doctor Who?
Mark: I was asked to do it. I didn’t even have to audition, they just asked me to do it. That’s probably because I was on a series called Battlestar Galactica and a series called Firefly and a series called Dollhouse which were known to the writers and producers of Doctor Who. I probably had the coolest role in Battlestar. It was the hardest, strangest role I’ve ever done.
from Doctor Who: Mark Sheppard In A Unique Interview on SFX
Firefly, Dollhouse, and Battlestar.