Captain Jack Harkness: "You missed me, right?"

More than you could possibly imagine. Must compliment the production crew for being able to keep Jack's appearance a secret, in today's world. Though, I thought that his appearance was a bit random. Even a bit distracting from the main plot, which deals with Jo Martin from Holby City being revealed to be a previously unknown incarnation of the Doctor. My one real beef with this story is that I couldn't go in blind, as, while I'm only watching it now for the first time, it aired months ago (with the twist being all over the internet). Would've been fun to have gone into it, not knowing that Ruth was the Doctor.

I don't mind the reveal of a previously unknown incarnation of the Doctor. It's not something that has no basis in the show until now. Not only did we have the War Doctor a few years back, but The brain of Morbius had shown images of what appeared (and, apparently, was intended) to be previously unseen incarnations of the Doctor.