Doctor Who (2013 specials) Doctor", saw the departure of Smith from the series and the introduction of Peter Capaldi as the Twelfth Doctor. "The Day of the Doctor" features the return of the Zygons for the first time since "Terror of the Zygons" in 1975. "The Time of the Doctor" draws together a number of plot threads that have run through the series since the Eleventh Doctor's first episode in 2010. <onlyinclude></onlyinclude> In "The Day of the Doctor", Smith and Coleman star alongside David Tennant and Billie Piper; Tennant reprised his role as the Tenth Doctor, while Piper, although credited as playing Rose Tyler,
The Doctor (Doctor Who) been explained. An essay in the "About Time" episode guides by Lawrence Miles and Tat Wood suggests that Time Lords are somehow exempt from the effect by their very nature. Rose Tyler is seen holding an infant version of herself in "Father's Day", with no visible energy discharge, but the contact does allow the Reapers to enter the church in which the Doctor and several others are taking refuge. While doing a live commentary on the episode at the 2006 Bristol Comic Expo, episode author Paul Cornell said that this is supposed to be due to the Blinovitch Limitation Effect,