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,
Companion (Doctor Who) "what constitutes a Doctor Who companion is no longer clear". During the Doctor's latest incarnations, his primary companions, such as Rose Tyler and Martha Jones, have fulfilled a distinct dramatic role, more significant than other, less-prominent TARDIS travellers such as Adam, Jack, and Mickey. The British press referred to Martha as the "first ethnic minority companion in the 43-year television history of "Doctor Who"" and the "first black assistant", despite the presence of Mickey Smith in the previous season—including several episodes in which he travelled in the TARDIS with the Doctor. Similarly, some characters who appear to qualify as companions